Collections: Fortification, Part II: Romans Playing Cards

This is the second part of a five part (I) series covering some of the basics of fortifications, from city walls to field fortifications, from the ancient world through the modern period. Last time, we looked as the ancient besieger’s playbook (both the motives and options for taking walled cities) through a case study of Assyrian siege methods. This week, we’re going to move forward several centuries to look at Roman fortifications, in particular how Roman methods of fortification changed to meet different objectives within different strategic environments, a good example of how what one is trying to do with a fortification alters the form that the fortification takes.

The Romans were, of course, building fortification for a very long time; we’re going to start with Roman fortified camps no later than the second century BC (probably also in use in the third century) and march all the way forward to Roman legionary fortresses in the fourth and fifth centuries AD, focusing on the ways that the changing strategic environment alters the overall aims of these fortifications which in turn influences their physical structure (but within a pre-existing framework established by past practice and assumptions).

As always, if you like what you are reading here, please share it; if you really like it, you can support me on Patreon. And if you want updates whenever a new post appears, you can click below for email updates or follow me on twitter (@BretDevereaux) for updates as to new posts as well as my occasional ancient history, foreign policy or military history musings.

Ace of Spades

Now when we talk about the evolution of Roman forts, it is important to be clear that the Romans (and their Mediterranean contemporaries) already had a well developed tradition of city fortification (and we’ll look at perhaps the greatest example of that tradition at the beginning of next week). Sophisticated walled cities in the Hellenistic period (323-31 BC) typically a stone curtain wall running the perimeter of the city (much like the one at Jericho; these could be very substantial – the 4th century BC walls of Rome were up to 10m high and 3.5m thick, made out of tufa), supported by projecting towers that might mount not only archers but also catapults and be further defended by a combination of defensive ditches and out-walls.

So the Romans have access (filtering in through the successor states; the Romans were voracious adopters of foreign military technology) to all of those techniques already, so the decision in some cases to not use them is a conscious choice (although in some cases the reason for that choice may well be ‘tradition and inertia’).

But we’re not going to start with Roman city walls, but rather with Roman marching forts. The degree to which we should understand the Roman habit of constructing fortified marching camps every night as exceptional is actually itself an interesting question. Our sources disagree on the origins of the Roman fortified camp; Frontinus (Front. Strat 4.1.15) says that the Romans learned it from the Macedonians by way of Pyrrhus of Epirus but Plutarch (Plut. Pyrrhus 16.4) represents it the other way around; Livy, more reliable than either agrees with Frontinus that Pyrrhus is the origin point (Liv. 35.14.8) but also has Philip V, an capable Macedonian commander, stand in awe of Roman camps (Liv. 31.34.8). It’s clear there was something exceptional about the Roman camps because so many of our sources treat it as such (Liv. 31.34.8; Plb. 18.24; Josephus BJ 3.70-98). Certainly the Macedonians regularly fortified their camps (e.g. Plb. 18.24; Liv 32.5.11-13; Arr. Alex. 3.9.1, 4.29.1-3; Curtius 4.12.2-24, 5.5.1) though Carthaginian armies seem to have done this less often (e.g. Plb. 6.42.1-2 encamping on open ground is treated as a bold new strategy).

It is probably not the camps themselves, but their structure which was exceptional. Polybius claims Greeks “shirk the labor of entrenching” (Plb. 6.42.1-2) and notes that the stakes the Romans used to construct the wooden palisade wall of the camp are more densely placed and harder to remove (Plb. 18.18.5-18). The other clear difference Polybius notes is the order of Roman camps, that the Romans lay out their camp the same way wherever it is, whereas Greek and Macedonian practice was to conform the camp to the terrain (Plb. 6.42); the archaeology of Roman camps bears out the former whereas analysis of likely battlefield sites (like the Battle of the Aous) seem to bear out the latter.

In any case, the mostly standard layout of Roman marching camps (which in the event the Romans lay siege, become siege camps) enables us to talk about the Roman marching camp because as far as we can tell they were all quite similar (not merely because Polybius says this, but because the basic features of these camps really do seem to stay more or less1 constant.

Via Wikipedia, a diagram of the fairly standard layout of a Roman marching camp. The original caption goes thusly:
Basic ideal plan of a Roman castrum. (1) Principia; (2) Via Praetoria; (3) Via Principalis; (4) Porta Principalis Dextra; (5) Porta Praetoria (main gate); (6) Porta Principalis Sinistra; (7) Porta Decumana (back gate).

The basic outline of the camp is a large rectangle with the corners rounded off, which has given the camps (and later forts derived from them) their nickname: ‘playing card’ forts. The size and proportions of a fortified camp would depend on the number of legions, allied and auxiliaries present, from nearly square to having one side substantially longer than the other. This isn’t the place to get into the internal configuration of the camp, except to note that these camps seemed to have been standardized so that the layout was familiar to any soldier wherever they went, which must have aided in both building the camp (since issues of layout would become habit quickly) and packing it up again.

Now a fortified camp does not have the same defensive purpose as a walled city: the latter is intended to resist a siege, while a fortified camp is mostly intended to prevent an army from being surprised and to allow it the opportunity to either form for battle or safely refuse battle. That means the defenses are mostly about preventing stealthy approach, slowing down attackers and providing a modest advantage to defenders with a relative economy of cost and effort.

In the Roman case, for a completed defense, the outer most defense was the fossa or ditch; sources differ on the normal width and depth of the ditch (it must have differed based on local security conditions) but as a rule they were at least 3′ and 5′ wide and often significantly more than this (actual measured Roman defensive fossae are generally rather wider, typically with a 2:1 ratio of width to depth, as noted by Kate Gilliver. The earth excavated to make the fossa was then piled inside of it to make a raised earthwork rampart the Romans called the agger. Finally, on top of the agger, the Romans would place the valli (‘stakes) they carried to make the vallum. Vallum gives us our English word ‘wall’ but more nearly means ‘palisade’ or ‘rampart’ (the Latin word for a stone wall is more often murus).

Polybius (18.18) notes that Greek camps often used stakes that hadn’t had the side branches removed and spaced them out a bit (perhaps a foot or so; too closely set for anyone to slip through); this sort of spaced out palisade is a common sort of anti-ambush defense and we know of similar village fortifications in pre- and early post-contact North America on the East coast, used to discourage raids. Obviously the downside is that when such stakes are spaced out, it only takes the removal of a few to generate a breach. The Roman vallum, by contrast, set the valli fixed close together with the branches interlaced and with the tips sharpened, making them difficult to climb or remove quickly.

The gateway obviously could not have the ditch cut across the entryway, so instead a second ditch, the titulum was dug 60ft or so in front of the gate to prevent direct approach; the gate might also be reinforced with a secondary arc of earthworks, either internally or externally, called the clavicula; the goal of all of this extra protection was again not to prevent a determined attacker from reaching the gates, but rather to slow a surprise attack down to give the defender time to form up and respond.

And that’s what I want to highlight about the nature of the fortified Roman camp: this isn’t a defense meant to outlast a siege, but – as I hinted at last time – a defense meant to withstand a raid. At most a camp might need to withstand the enemy for a day or two, providing the army inside the opportunity to retreat during the night.

We actually have some evidence of similar sort of stake-wall protections in use on the East Coast of Native North America in the 16th century, which featured a circular stake wall with a ‘baffle gate’ that prevented a direct approach and entrance. The warfare style of the region was heavily focused on raids rather than battles or sieges (though the former did happen) in what is sometimes termed the “cutting off way of war” (on this see W. Lee, “The Military Revolution of Native North America” in Empires and Indigines, ed. W. Lee (2011)). Interestingly, this form of Native American fortification seems to have been substantially disrupted by the arrival of steel axes for presumably exactly the reasons that Polybius discusses when thinking about Greek vs. Roman stake walls: pulling up a well-made (read: Roman) stake wall was quite difficult. However, with steel axes (imported from European traders), Native American raiding forces could quickly cut through a basic palisade. Interestingly, in the period that follows, Lee (op. cit.) notes a drift towards some of the same methods of fortification the Romans used: fortifications begin to square off, often combined a ditch with the palisade and eventually incorporated corner bastions projecting out of the wall (a feature Roman camps do not have, but later Roman forts eventually will, as we’ll see).

Illustration in 1585 by John White of the Native North American village of Pomeiooc, in modern North Carolina. Note the wood-stake palisade, with short intervals between the stakes. The Roman vallum seems to be much more densely set than this but one wonders if this style of fortification approximates how a Greek or Macedonian camp might be defended.

Roman field camps could be more elaborate than what I’ve described; camps often featured, for instance, observation towers. These would have been made of wood and seem to have chiefly been elevated posts for lookouts rather than firing positions, given that they sit behind the vallum rather than projecting out of it (meaning that it would be very difficult to shoot any enemy who actually made it to the vallum from the tower).

Via Wikipedia, remains of one of the Roman forts used in the siege of Masada (72-3AD), still showing the distinctive playing-card shape.

When a Roman army laid siege to a fortified settlement, the camp formed the ‘base’ from which siege works were constructed (particularly circumvallation – making a wall around the enemy’s city to keep them in – and contravallation – making a wall around your siege position to keep other enemies out. We’ll discuss these terms in more depth a little later). Some of the most elaborate such works we have described are Caesar’s fortifications at the Siege of Alesia (52 BC; Caes. B.G. 7.72). There the Roman line consisted of an initial trench well beyond bow-shot range from his planned works in order to prevent the enemy from disrupting his soldiers with sudden attacks, then an agger and vallum constructed with a parapet to allow firing positions from atop the vallum, with observation towers every 80 feet and two ditches directly in front of the agger, making for three defensive ditches in total (be still Roel Konijnendijk‘s heart! – but seriously, the point he makes on those Insider “Expert Rates” videos about the importance of ditches are, as you can tell already, entirely accurate), which were reinforced with sharpened stakes faced outward. As Caesar expressly notes, these weren’t meant to be prohibitive defenses that would withstand any attack – wooden walls can be chopped or burned, after all – but rather to give him time to respond to any effort by the defenders to break out or by attackers to break in (he also contravallates, reproducing all of these defenses facing outward, as well).

Deciding to Stand

The end of the reign of Augustus (in 14AD) is a convenient marker for a shift in Roman strategic aims away from expansion and towards a ‘frontier maintenance.’ The usual term for both the ROman frontier and the system of fortifications and garrisons which defended it is the limes (pronounced lim-ees), although this wasn’t the only word the Romans applied to it. I want to leave aside for a moment the endless, complex conversation about the degree to which the Romans can actually be said to have strategic aims, though for what it is worth I am one of those who contends that they did.2 We’re mostly interested here in Roman behavior on the frontiers, rather than their intent anyway.

Via Wikipedia, a useful model of the Roman legionary fortress Deva Victrix at what is today Chester, England; the stone-walled fort here was constructed by Legio XX Valeria Victrix beginning in 88 AD. This particular fort would have supported Hadrian’s wall and also projected power into modern Wales, but is itself a bit more than a hundred miles away from the former. Note also both the retention of the ‘playing card’ shape but also how the towers do not project out from the wall, leaving no way to fire on enemies standing at the base of the wall.

What absolutely does begin happening during the reign of Augustus and subsequently is that the Roman legions, which had spent the previous three centuries on the move outside of Italy, begin to settle down more permanently on Rome’s new frontiers, particularly along the Rhine/Danube frontier facing Central and Eastern Europe and the Syrian frontier facing the Parthian Empire. That in turn meant that Roman legions (and their supporting auxiliary cohorts) now settled into permanent forts.3

Via WIkipedia, a diagram of a fairly standard imperial-period Roman fort, with its standard ‘playing card’ shape. While the Roman word for these camps was castra which gives us our word ‘castle,’ describing this as a castle as the caption does mistakes its purpose.

The forts themselves, at least in the first two centuries, provide a fairly remarkably example of institutional inertia. While legionary forts of this early period typically replaced the earthwork-and-stakes wall (the agger and vallum) with stone walls and towers and the tents of the camp with permanent barracks, the basic form of the fort: its playing-card shape, encircling defensive ditches (now very often two or three ditches in sequence) remain. Of particular note, these early imperial legionary forts generally still feature towers which do not project outward from the wall, a stone version of the observation towers of the old Roman marching camp. Precisely because these fortifications are in stone they are often very archaeologically visible and so we have a fairly good sense of Roman forts in this period. In short then, put in permanent positions, Roman armies first constructed permanent versions of their temporary marching camps.

And that broadly seems to fit with how the Romans expected to fight their wars on these frontiers. The general superiority of Roman arms in pitched battle (the fancy term here is ‘escalation dominance’ – that escalating to large scale warfare favored the heavier Roman armies) meant that the Romans typically planned to meet enemy armies in battle, not sit back to withstand sieges (this was less true on Rome’s eastern frontier since the Parthians were peer competitors who could rumble with the Romans on more-or-less even terms4; it is striking that the major centers in the East like Jerusalem or Antioch did not get rid of their city walls, whereas by contrast the breakdown of Roman order in the third century AD and subsequently leads to a flurry of wall-building in the west where it is clear many cities had neglected their defensive walls for quite a long time). Consequently, the legionary forts are more bases than fortresses and so their fortifications are still designed to resist sudden raids, not large-scale sieges.
Via Wikipedia, a map of the Roman limes in Germania Superior and Raetia, an area known to the Romans as the agri decumates. Notice how the major legionary bases at Trier, Mainz, Strasbourg and Vindonissa are well behind the frontier itself, but positioned on clear road networks which allow them to rapidly concentrate and respond to any incursion.

They were also now designed to support much larger fortification systems, which now gives us a chance to talk about a different kind of fortification network: border walls. The most famous of these Roman walls of course is Hadrian’s Wall, a mostly (but not entirely) stone walls which cuts across northern England, built starting in 122. Hadrian’s walls is unusual in being substantially made out of stone, but it was of-a-piece with various Roman frontier fortification systems. Crucially, the purpose of this wall (and this is a trait it shares with China’s Great Wall) was never to actually prevent movement over the border or to block large-scale assaults. Taking Hadrian’s wall, it was generally manned by something around three legions (notionally; often at least one of the legions in Britain was deployed further south); even with auxiliary troops nowhere near enough to actually manage a thick defense along the entire wall. Instead, the wall’s purpose is slowing down hostile groups and channeling non-hostile groups (merchants, migrants, traders, travelers) towards controlled points of entry (valuable especially because import/export taxes were a key source of state revenue), while also allowing the soldiers on the wall good observation positions to see these moving groups. You can tell the defense here wasn’t prohibitive in part because the main legionary fortresses aren’t generally on the wall, but rather further south, often substantially further south, which makes a lot of sense if the plan is to have enemies slowed (but not stopped) by the wall, while news of their approach outraces them to those legionary forts so that the legions can form up and meet those incursions in an open battle after they have breached the wall itself. Remember: the Romans expect (and get) a very, very high success rate in open battles, so it makes sense to try to force that kind of confrontation.

This emphasis on controlling and channeling, rather than prohibiting, entry is even more visible in the Roman frontier defenses in North Africa and on the Rhine/Danube frontier. In North Africa, the frontier defense system was structured around watch-posts and the fossatum Africae, a network of ditches (fossa) separating the province of Africa (mostly modern day Tunisia) from non-Roman territory to its south. It isn’t a single ditch, but rather a system of at least four major segments (and possibly more), with watch-towers and smaller forts in a line-of-sight network (so they can communicate); the ditch itself varies in width and depth but typically not much more than 6m wide and 3m deep. Such an obstruction is obviously not an prohibitive defense but the difficulty of crossing is going to tend to channel travelers and raids to the intentional crossings or alternately slow them down as they have to navigate the trench (a real problem here where raiders are likely to be mounted and so need to get their horses and/or camels across).

On the Rhine and the Danube, the defense of the limes, the Roman frontier, included a border wall (earthwork and wood, rather than stone like Hadrian’s wall), similarly supported by legions stationed to the rear, with road networks positioned; once again, the focus is on observing threats, slowing them down and channeling them so that the legions can engage them in the field. This is a system based around observe-channel-respond, rather than an effort to block advances completely.

Refusing to Fold

As we move into the later Roman Empire, particularly after the Crisis of the Third Century (235-284 AD), we start to see changes in the form of Roman forts. Two things had been happening of the course of the Crisis (and in some cases before it) which transformed the Roman frontier situation. First, Rome’s enemies had gotten quite a bit stronger: in the west, long exposure to Rome had led the various ‘barbarians’ on the other side of the limes to both pick up elements of Roman military practice but also to form into larger and larger political units (in part in order to hold off Roman influence) which were more dangerous. In the east, the Parthian Empire had collapsed in 224 to be replaced by the far more capable and dangerous Sassanid Empire. At the same time, fifty years of civil war had left Rome itself economically and militarily weaker than it had been. Bigger threats combined with scarcer state resources enforced a more flexible approach to controlling the borders.

In particular, Roman forces could no longer be entirely sure they would possess escalation dominance in any given theater. Indeed, during the Crisis, with legions being peeled to fight endless internal wars between rival claimants had meant that major frontier problems might go under-resourced or even entirely unaddressed for years. While the reign of Diocletian (284-311) marked a return to Roman unity, quite a bit of damage had already been done and by the end of the third century we see changes in patterns of fortification that reflect that.

The changes seem fairly clearly to have been evolutionary, in part because many older legionary forts remained in use. Some of the first things we see are traditional ‘playing-card’ forts but now with the neat rectangular shape disrupted by having the towers project out from the walls. The value of a projecting tower (as we’ll discuss more in the next part) is that soldiers on the tower, because it projects outward, can direct missiles (arrows, javelins, slings, etc) down the length of the wall, engaging enemies who might be trying to scale the wall or breach it. Of course a fortress that is now being designed to resist enemies scaling or breaching large stone walls is no longer worried about a raid but rather being designed to potentially withstand a serious assault or even a siege. Defensive ditches also multiply in this period and increase in width, often exceeding 25ft in width and flat-bottomed; the design consideration here is probably not to stop a quick raid anymore but to create an obstacle to an enemy moving rams or towers (think back to our Assyrians!) close to the walls.
From the Programme Interreg V-A Romania-Bulgaria 2014-2020 an aerial photograph of the remains of the Roman legionary fortress at Capidava on the Danube in what is today Romania, who I very much hope, since their objective is “the development, enhancement and innovation of the tourism product of the common Roman heritage” will not much mind me reproducing their photograph of this shockingly well preserved Roman fort that I now very much want to visit.
This is a great example where what was initially a Roman ‘playing card’ legionary fort has been overbuilt with thickened walls and projecting towers. Note how the square towers at the center of the walls were originally gatehouses which have been converted into projecting defenses towers to leave fewer points of entry to defend.

Over time, forts also tended to abandon the ‘playing-card’ proportions and instead favor circular or square shapes (minimizing perimeter-to-defend for a given internal area). And while even the original Roman marching camps had been designed with a concern to make it hard for an enemy to fire missiles into the camp – using the trench to keep them out of range and keeping an interval (literally the intervallum, the ‘inside the wall’) between the vallum and the buildings so that any arrows or javelins sent over the walls would land in this empty space – later Roman fortresses intensify these measures; we even see fortresses like the one at Visegrád shown below incorporate its internal structures into the walls themselves, a measure to make the troops within less vulnerable to missile fire in a siege; this style becomes increasingly common in the mid-fourth century. Finally, by the fifth century we start to see the sites of Roman forts changing too, especially in the western part of the empire, with forts moving from low-land positions along major roadways (for rapid response) to hilltop sites that were less convenient for movement but easier to defend (in the East, a lot of the focus shifts to key heavily fortified cities – essentially fortress cities – like Nisibis (modern Nusaybin), Amida, Singara and Dara. We’ll talk a bit more about how a heavily fortified late-Roman city might be protected in the next post.

Via Wikipedia, a smaller Roman fort at Visegrád, reflective of late fourth century trends in Roman fort design. Notice the projecting towers on the corners, which allow the defenders to shoot missiles all the way down the walls.

In short, Roman forts in this late period are being designed with the ability to resist either serious assaults or prolonged sieges. This in part reflects a lack of confidence that the Romans could always count on being able to immediately force a field battle they could win; while Roman armies retained the edge through most of this period, the main field armies were increasingly concentrated around the emperors and so might be many days, weeks or even months away when an incursion occurred; local forces had to respond elastically to delay the incursion much longer than before until that army could arrive.

Now of course the downside to a focus like this on single-site defense (‘point defense’ in its most basic form) is that the enemy army is given much more freedom to move around the countryside and wreck things, where they would have been engaged in the older observe-channel-respond defense system much more quickly (Luttwak terms this ‘preclusive’ defense, but it isn’t quite that preclusive; the frontier is never a hard border). But of course the entire reason you are doing this is that the shifting security situation means you can no longer be confident in winning the decisive engagement that the observe-channel-respond defense system is designed for; you need to delay longer to concentrate forces more significantly to get a favorable outcome. Single-site defenses can do this for reasons we’ve actually already discussed: because the army in the fort remains an active threat, the enemy cannot generally just bypass them without compromising their own logistics, either their supply lines or foraging ability. Consequently, while some forts can by bypassed, they cannot all be bypassed (a lesson, in fact, that the emperor Julian would fail to learn, leading to disaster for his army and his own death).

And so the enemy, while they can damage the immediate environment, cannot proceed out of the frontier zone (and into the true interior) without taking some of these forts, which in turn will slow them down long enough for a major field army to arrive and in theory offer battle on favorable terms.

While it is easy to discount these shifts as just part of the failure of the Roman Empire (and we’ll come back to this idea, often presented in the form of a misquotation of George S. Patton that ‘fixed fortifications are monuments to the stupidity of man’ though what he actually said was merely that the Maginot line was such), they contributed meaningfully to the Roman ability to hold on to a vast empire in an increasingly more challenging security environment. At pretty much all stages of its development, Roman fortification on the frontiers was designed to allow the Romans to maintain their territorial control with an economy of force precisely because the Roman Empire could not afford to maintain overwhelming force everywhere on its vast perimeter. Rome wasn’t alone in deploying that kind of defensive philosophy; at any given point the northern frontier of China was guarded on much the same principles: the need to hold a frontier line with an economy of force because no state can afford to have overwhelming force everywhere. In both cases, the need for defense was motivated in no small by the impossibility of further offensive; in the Roman case, further extension of the limes would simply create more territory to defend without actually creating more revenue with which to defend it (this is why the Roman acquisition of Dacia and much of Britain were likely ill-conceived, but then both operations were politically motivated in no small part) while in the Chinese case, the logistics of the steppe largely prohibited further expansion.

This Roman system, combining local single-site defenses (which included a proliferation of walled towns as the population centers of the western empire frantically rebuilt their walls) with concentrated mobile field armies really only began to fail after the Battle of Adrianople (378), where to be clear the fortification system worked fine, the error came from the emperor Valens’ stupid decision to attack before his co-emperor Gratian could arrive with reinforcements (Valens was eager to get all of the credit and so he takes all of the blame).

Next time, we’ll actually begin to turn to what I suspect you all had in mind when I started writing this: point defenses aiming to defend an individual town or residence (read: castles and walled cities) and how they could be structured to resist attack in the pre-gunpowder era and we’ll get into the function of curtain walls, outworks, towers, citadels and so on.

  1. Please do note, not entirely constant. Changes in the organizational structure of the legions are reflected in the structure of the camp. For more on this and Roman camps in general, check out M. Dobson, The Army of the Roman Republic: The Second Century BC, Polybius and the Camps at Numantia, Spain (2008) and while Polybius insists that Roman camps never bow to the terrain, they clearly do sometimes. So they aren’t perfectly consistent, but they are remarkably consistent.
  2. One of these days I may get around to writing about the debate; in the meantime, for a ‘quick’ primer on it, look up J.E. Lendon, “Primitivism and Ancient Foreign Relations” CJ 87.4 (2002): 375-384. For a long primer on it, there is little substitute for E.L. Wheeler, “Methodological Limits and the Mirage of Roman Strategy” JMH 57.1 (1993): 7-41 and 52.2 (1993): 215-240).
  3. The formulation here and the thinking in terms of what the various elements of the Roman system were intended to accomplish goes back to E.N. Luttwak’s The Grand Strategy of the Roman Empire (1976), the book that initiated the long-running strategy debate mentioned above. It is not without its own problems and again I’d direct you to the two articles in the previous note to read about that. Nevertheless, as an overview of the Roman frontier defense system, I think the basic description that follows holds up (the main debate is less about the structure of the system and more about the intent of it in any event).
  4. The Romans win those rumbles more often than they lose, but it is hardly a one-sided affair!

121 thoughts on “Collections: Fortification, Part II: Romans Playing Cards

  1. Pardon me if this is a dumb question, but what exactly were Roman forts in North Africa meant to defend against? You say it’s mostly to protect against non-Roman territory to the south of places like Tunisia, but isn’t that the middle of the Sahara desert? Did people actually live there to raid against the Romans?

    1. Yes. The Romans struggled to project power meaningfully into the arid and desert regions. So tribes of the Garamantes and Gaetuli that were outside of the well controlled parts of Africa proconsularis could potentially raid into the are controlled areas.

      Remember that on most frontiers, imperial power doesn’t stop at a bright line, but fades out slowly.

      1. The observation about how imperial power fades toward a border always brings a question to my mind…

        How would an archaeologist, some one to two thousand years from now, describe the post war 20th and 21st Century?

        Would they see a single or pair of empires whose authority fades or would they be able to see the intricate system of states and allies?

        This question presupposes that for some reas little or no historical record survives. (Maybe someone starts burning silicon wafers for energy.)

        1. They may be able to follow NATO/Warsaw Pact ammunition standards to see who was on what side, though with occasional misleading results – but the drop-off of Soviet supply/control decades previous to American-fronted NATO’s dissolution should be fairly clear.

          1. I don’t know about silicon wafers, but that’s certainly true of optical storage (CDs, DVDs). I suppose videotapes, too. Even worse is the loss of the software needed to translate the storage media to output. Can we still read Hollerith punched tapes? Certainly not all of them.

          2. Software can be reconstructed. If we have a physical record it may be readable. Once you have a bilingual

        2. The problem is, not all our news is stored digitally. Not even close. One milk crate of newspapers and magazines an old dude stuck in his dry attic for storage just in case they ever became useful could provide more literary sources from the modern world than historians have from entire empires.

          Sure, most printed material would be lost to rot, fire, vermin, etc, but we have so much printed material lying around, even disregarding stuff we printed specifically to survive long periods of time (e.g. time capsules). A quick Google search suggests that hundreds of millions of magazines, billions of books, and dozens of billions of newspapers are printed every year; even the fraction of that lucky enough to survive a century is probably more than the volume of documents produced by the Roman Empire in any given year. Possibly even the entire world before the modern era?

          Anyways, ignoring literary evidence, I’m not sure how much pure archaeology could discover about our world. It’s entirely possible that they’d assume the entire world was controlled by one empire/federation, considering how the same structures keep popping up across the entire planet. “Why would these distinctive buildings with the M-sigil appear around the entire globe, in almost identical configurations, if they weren’t all controlled by the same polity?”

          …assuming that the future doesn’t have McDonalds or other fast food franchises. Which I guess brings us to the question, how much would the future archaeologists know about the modern world due to their future being similar? Or, for that matter, assume from their future world being different? For instance, would they give up any hope of figuring out culture or political allegiance based on material evidence since everyone buys and sells with everyone, even their strategic enemies? I mean, it would be unprofitable to not do that, surely anyone with the technological ability to make internal combustion engines would be smart enough to recognize that?

          1. I know there is archival paper, but does most modern paper fare better over 2000 years than papyrus? I’m not sure it does.

          2. Landfills can be surprisingly anoxic; old newspapers have been dug out of them virtually intact.

          3. It doesn’t have to. We produce orders of magnitude more documents than were produced during the papyrus era. Areas as dry as Egypt will preserve as much paper as Egypt did papyrus, and even if it takes a freak series of coincidences to preserve anything in wetter areas, we’re producing enough newspapers, books, magazines, etc that those coincidences will preserve some things.

          4. Problem is that modern paper isn’t all that good at survival. It tends to be somewhat acidic, and it is, well, paper, both of which mean that it falls apart rather quickly. Parchment can survive for a long time, especially in dry conditions. Paper? Unlikely, unless it is buried in completely anaerobic conditions (e.g. wet earth – but even then the data on it may be lost even if the paper itself survives).

        1. The stereotypical stark transitions between desert and grassland are almost always a side effect of human interventions. And we know that prior to Carthaginian agricultural development, the area was lush enough to support wild elephant populations.

        2. By some definitions of pastoral. “Desert” doesn’t necessarily mean absolutely uninhabitable sand dunes and rocks. In general any place too dry to support grass cover is considered desert, but that includes scrublands that can support hardy browsers like goats, camels and donkeys, provided that herdsmen can lead them to water and to rotate their pastorage.

    2. Peoples like the Tuareg or the Berber are able to keep the central states of that area at arms length even today. I guess if they can do it, their predecessors would have had an even easier time.

  2. Is this series going to eventually cover star forts and the like? I find them so fascinating and they really seem like something unique in the world of fortifications.

    1. Preemptive recommendation: Christopher Duffy’s “Fire & Stone: The Science of Fortress Warfare 1660-1860” is an engaging little primer on fortresses and siege warfare of that period (and even includes some wargaming rules in an appendix if you want to try it out yourself.)

  3. I’m curious; how long would it take a Roman army to set up a camp? Obviously, a legion is a big group of soldiers and many hands make light work, but it still must have taken hours out of the day to dig a ditch and drive stakes into the ground, on top of setting up tents, preparing food, maintaining equipment, and other such activities.

    1. Don’t underestimate their incentive.

      During the American Civil War, there are cases where troops literally refused to stop carrying their shovels because they entrenched every night.

    2. Without looking up details in my books, I am suggesting from memory that the legion stopped march in mid-afternoon, 15 to 20 miles covered, and then spent four to five hours erecting its camp for the night. If this is grossly wrong, corrections welcome!

      1. That’s a lot of effort going on guarding against an evenings surprise attack, that could have gone into marching further.

        Did other armies make similarly time consuming efforts, or were the legions especially vulnerable to being taken by surprise? Are we praising their military engineering, when we should be dissing their scouts and sentries?

        1. The legionaries, as Prof. Devereux alluded to, were heavy infantry. They relied on being to defeat their opponents by man-to-man superiority in close combat. They did not rely so much on speedy maneuver or deception or any of the techniques used by lighter forces. The nightly fortified camp fit well into their basic mode of operation.

          1. Heavy infantry or not, slowing your army down by a third seems quite a significant sacrifice. So it looks like there must have been quite a considerable risk of a surprise attack to justify slowing the army down so much.

          2. I don’t know how “considerable” the chance of a night attack was; of course an enemy can attack at a time of their choosing while defenders have to stay alert. But the fact that the camp WAS secure discouraged such attacks. Sentries could keep watch and sound an alert if necessary and in the meantime the troops could get an unworried night’s sleep, which was probably important enough to health and morale to justify the reduction in millia marched per day.

          3. IIRC Emperor Nicephorus I was killed and the Byzantine army defeated catastrophically by the Bulgars in a night attack, when they had failed to build a proper fortified camp. All after having sacked the Bulgar capital.

          4. Hypothesis:

            I can’t prove this but I suspect it…

            Roman legionnaires carried very heavy loads, and their daily marching pace was already comparable to that of most ancient armies even if they were stopping to build a fort every day.

            Imagine two legions.

            The First Legion tries to maximize distance covered by sacrificing its daily entrenchment at a new fortified camp. Consequently, it marches for another four hours a day, carrying the heavy packs of “Marius’ mules” all the way.

            The First Legion then stops off at the end of the day in a disorderly, unfortified, hastily prepared camp. The men sleep unsoundly for fear of night attacks, while dealing with less sanitary latrine trenches and so on because there’s no routine, standardized practice of laying out a well-structured camp. This is particularly hard on the men who are suffering from minor injuries or illness, for whom this pace is particularly grueling.

            The Second Legion slows down and digs a fortified camp every day. The men have to do more shoveling, but they also get better sleep and probably sleep in better, more sanitary conditions, and they do significantly less daily route-marching while carrying giant knapsacks, big plywood shields, and so on, because once they reach the camp site they can put most of that stuff down to be guarded by a relative handful of men.

            Furthermore, the centurions aren’t stupid and know which of their men should probably be on light duty for the sake of conserving their health and stamina. So they can assign those men to light duty like “guard everyone’s backpacks and this giant pile of shields while the rest of the unit digs trenches.”

            On a long campaign, the Second Legion may be significantly more effective than the First, even if it doesn’t have as much strategic mobility.

            This is especially true because that extra strategic mobility matters most in two situations: enemy territory, and quick marches through Roman territory.

            On a quick march (say, to reinforce a threatened province along hundreds of miles of Roman roads), well, you’re passing through friendly territory. Often, your marching troops will encounter friendly installations where the men can barrack for the night. Or at least the remains of an existing legionary camp that can be hastily repurposed- much of the work is already done for you and you just have to pitch new tents, cut new stakes, and maybe square up the existing ditch and rampart. You’re not doing as much work this way as you would if you build a new fort from scratch, at least not on average.

            In enemy territory, the reduced strategic mobility and increased burden of building a fort every day hits you full-blast… But this is also exactly the time when even a small wandering enemy force can really mess you up by launching a night attack into your poorly prepared camp, or by picking off the inevitable stragglers who can’t quite keep up when the legion is trying to march continuously for thirty miles and 10-12 hours a day. Which is when a more leisurely pace and more fort-building starts to really come in handy…

          5. I doubt that Roman armies could have marched faster, consistently, if they didn’t build camps.

            My understanding, from previous posts here by our pedantic host and recollection from history books, is that Roman armies would aim for 40km a day at most. In the medieval period armies slowed down, and in the early part of 1914 the German infantry on the far right wing who had the furthest to travel maxed out at 40km a day. A quick search for current 21st C Australian Army guidelines suggests about the same 40km limit.

            (For those who haven’t converted to metric yet, that’s about 8.3 leagues or 87500 cubits a day.)

            If you’re a hiker you might be thinking you can do better than that. Sure, but most people don’t hike with armour and weapons.

            There’s also the time lost to various logistics and organisation aspects, explained by our host in


            If your troops have a few hours to spare each day, whether that’s due to fundamental human physical limits or organisational grit, it doesn’t hurt to spend it building fortifications that just might avoid disaster.

        2. Adding to the excellent replies you’ve already gotten, speaking as someone who has done his military service as a rifleman, 15-20 miles a day is an excellent pace over time.

          40 km (25 miles) a day is workable for small units of well-trained soldiers with a light load, no more than 10-20 kg. Just for perspective: If the individual soldier is wearing ceramic plating and the section is bringing section-level weaponry (e.g. a light machine gun, underslung grenade launchers), the upper limit of that intervall barely leaves room for a few changes of socks and a light tent. Though I’m not expert, I would be unsurprised if the Roman legionnary’s individual load was heavier than the modern rifleman.

          If you’re moving off road, but still light terrain, a pace of anything close to 40 km/day is going to be very hard to sustain even for very small and exceptionally trained units. While on the road, the hard surface means that even well-trained soldiers has an increased risk of injury. Gaining a few extra miles a day isn’t really helpful if you suffer increasing casualties from things like severe blisters or even osteomyelitis.

          Then you add cumulative fatigue into the equation, and trying for a fast pace is going to sap your fighting strength very quickly.

          Marching from late in the morning until early afternoon, spending the evening fortifying, and then having a good night’s rest sounds like a plausible way to balance mobility, safety and maintaining fighting strength. Marching through the day for any extended period, on the other hand, is an excellent way to ensure the majority of your force has a reduced ability to fight, while a significant minority is unable to fight at all.

          1. On the fantasy side of things, _Nature of Middle-earth_ has a brief note by Tolkien on the superior mobility of elves due to the greater stamina and speed of elves (and, for some reason, their horses.) So Eol doing “only” 70 miles a day on horseback, in ‘holiday’ mode. Up to 100 miles/day for a couple of days.

            The fantasy RPG Exalted’s tables of travel modes and speeds included lines like “tireless horse” or rowboat, with a modest hourly speed but never stopping, because magic.

          2. It’s also worth noting that the legion would be very spread out along the road between the two camps. The first soldiers to leave the previous night’s camp would depart around sunrise and arrive at the next camp site around midday. That’s before the end of the line had left the previous camp! The very last soldiers to leave the old camp would only arrive at the new one near dusk. There was not any significant part of the day in which some part of the army was not marching and filling up the road to its capacity.

            Unless you want some part of the army marching in the darkness (either before dawn or after dusk), or you build better roads (that can fit a wider column for the march’s entire length), you can’t really spend more time marching and less time fortifying. A unit marching with an army *must* spend a substantial amount of time waiting around, either for the roads to clear ahead or for the following units to catch up. Might as well spend some of that time building fortifications.

          3. “Adding to the excellent replies you’ve already gotten, speaking as someone who has done his military service as a rifleman, 15-20 miles a day is an excellent pace over time.”

            I was treating marching as requiring time and effort; and building a fortress as requiring time and effort. Which on the face of it suggests that reducing the time per day spent building would allow an increase in time per day spent marching.

            But I am perfectly prepared to accept that this is a naïve line of reasoning. After X hours of marching, an hour of fortress construction might well be easier than another hour of marching.

            But if I never ask a silly question, I never get a sensible answer.

        3. But it couldn’t have gone into marching further! A Legionary fully-loaded for the march is in a very different situation than a Legionary making camp or even standing watch; there’s only so long you can keep someone wearing that weight before they start to injure themselves and ‘lose’ armor and equipment.

          1. WWII cartoon: one soldier suggesting to another that the jokers in the playing cards are superfluous weight and should be thrown out.

    3. I may be mistaken, but I believe part of this may be addressed in some of the timing issues for a fairly large force. That is, your vanguard needs to start marching a significant amount of time before your rearguard can even begin, especially if you’re following a fairly narrow road. Therefore, your vanguard also needs to stop in time for the rearguard to catch up before they need to stop. I’m guessing therefore that part of the camp might be being broken down by those who haven’t begun marching and then is getting set up by those who’ve finished already?

      Not sure on timing though.

    4. As a follow-up: how much of the construction materials did the Romans carry with them, and how much did they locally source? Did they have to cut down whole forests whenever they set up a field camp?

      1. I was wondering this myself. Bret mentions “the Romans would place the valli (‘stakes) they carried to make the vallum.”

        The rest of the walls were made from dirt (I assume dug up on the spot). I’m not sure about gates, but one site says “Cut down trees were used for gates (about 15 meters wide) and watchtowers, which, after being constructed on-site, were placed on each of the four embankments (all of them were to be burnt the next day when the army set off on the road). ”


      2. My guess is they mostly carried tools (and other tools to sharpen them). A soldier had enough to carry already. Horses and mules had to be fed. Nails were a luxury in the pre-industrial era, you had big clumsy ones made by smiths and they were used for stuff like castle gates. Furniture was mostly made by *splitting* wood along the grain and wooden wedges. And forests were much more common back then. I haven’t heard about anyone transporting siege engines(they were built on site), and that sounds like much less wood! Maybe camels. Romans used camels, and they’re big and strong.

        Trees grow everywhere unless the soil is very poor. It might be worth investigating what Romans did in very rocky areas for example. Lack of industry and much lower populations back then limited how much you could cut.

      3. Each legionary would carry 2 palisade stakes along with his spear & pila, wore his armor with the shield on a carry strap and carried 3 days rations for himself, along with an entrenching tool. Josephus is referenced for this info.

    5. Similar to Veratrin, I’m also curious how often a legion on the move would be camping on completely fresh ground, versus rotating between previously-used spots a day’s march apart. Would the ditch and rampart be re-leveled when breaking camp, or left as they were? In the latter case, would they then be reused later, or would they deteriorate by the time the site might be useful again? How disruptive were the remains of pop-up one-night forts to the landscape and the rest of its inhabitants?

        1. Yeah, I thought the same. Imagine you’re counting on the fort being still there, and it is… but it’s occupied. Or just subtly sabotaged, like stakes half-cut at the base so they fall over if you push them. You could send scouts well ahead, but I don’t think it’s worth the risk if you already have the habit. And a song that goes well with it.

          1. Not the stakes, I’m assuming the legion carries away more or less everything they would have brought with them, which according to e.g. the Lannister kit review post includes the “large wooden stake[s] for field fortification (one per soldier)”. I’m not imagining intact camps left empty, I’m asking strictly about the dug ditch and piled rampart. Of course, if making a camp did require drawing on the surroundings for significant materials (beyond consumables like firewood) that might need to be destroyed when leaving, that’s also interesting and I’d be curious to know it.

      1. IIRC, the practice was to level the site before leaving. As noted above, a 10,000 person legionary army (5,000 legionaries plus 5,000 auxiliaries – not counting civilian hangers-on) takes time to form up and move off. The lead elements would be on the road while the last would be pushing dirt back into the ditches.

    6. John Peddie pg 75 of “the Roman War Machine” makes some estimates of elapsed time based on information for an advance of 10 miles. He works from information in Ceasar, “de Bello Gallico, II, 17-28.

      Basically the leading elements of the march contains surveyors who lay out the camp and start the work. As following elements arrive they will be put to work on setting up the camp. The 6 legions in this instance he estimates to be 22.5 miles in length when marching. Which of course would mean that there are still troops at the old camp site when the lead elements arrive at the new camp site.

  4. Finally, on top of the agger, the Romans would plave the valli (‘stakes) they carried to make the vallum.

    I assume they would *place the valli. Thanks for posting this, and I agree that it would be fun to learn about more modern fortifications like bastions.

  5. > sources differ on the normal width and depth of the ditch (it must have differed based on local security conditions) but as a rule they were at least 3′ and 5′ wide

    Should that be 3′ deep and 5′ wide?

  6. The early Roman focus on forts as bases and their dependence on Roman superiority in open battle reminds me of the American use of fire support bases in Vietnam, which almost always prevailed when the VC/NVA forces could be lured out to openly attack.

  7. Every time I think of projecting towers being used to fire upon attackers at the base of the wall I wonder about the attackers at the base of the tower. Some of them would be in view of the wall, but unless the tower projects to a point, which is not what I get from descriptions, diagrams, and photos, the tower itself would seem to cast a substantial shadow.

    1. You either throw javelins at them from the next tower over or you drop a big rock straight down on their heads.
      This’ll inform fortification design in the medieval and early modern eras so I expect it to come up in a later post.

    2. Indeed there were blind spots which could be dealt with by dropping things down the walls (which is why many castles have the top part of the wall project over the rest, there are holes for pouring stones or hot oil on attackers). After cannon became a major issue, bastion and star fortresses were developed with a shape that has no “dead zones”.

    3. In the medieval period, hoardings (made of wood) and later (medieval period IIRC) machicolations made of stone were used to make it easier for defenders to shoot/drop things downward. Both projected outward from the top of the wall. I’m not sure exactly when they came into use though.

  8. So since so much of this checks with my knowledge of 19thC British strategic choices, does anyone know if the British adopted basically the same strategy (fort-fleet-field army) because all of the Victorian officers learned Latin and Greek in their education and were reading Livy etc. to inform their own strategic choices, or is it the inexorable logic of empire?

    1. I thought the word “castle” came from the Latin word “castellum”, not from “castra” (at least not directly). At least wikipedia seems to think so too:

      Also interesting that English “wall” comes from “vallus”, but Dutch synonym “muur” and German synonym “Mauer” come from “murus”. I wonder if this difference in language has any significant historical background.

      Great read as always! Thank you.

  9. >Polybius (18.18) notes that Greek camps often used stakes that hadn’t had the side branches removed and spaced them out a bit (perhaps a foot or so; too closely set for anyone to slip through)(……..)Obviously the downside is that when such stakes are spaced out, it only takes the removal of a few to generate a breach.

    And the upside is that the gaps double as arrowslits. We have the image of hoplites when we read about ancient Greek warfare, but the fact they carried those big shields – hoplons – suggest missile warfare was widespread. Although maybe it was against slings. Stones might be easier to come by in Greece than trees.

    1. I’m being stupid. Greeks primarily used spears, whereas Romans favored short swords. Guess which works better for stabbing from behind a palisade? Besides, Romans were never renowned for their archers. I think they used auxillia for that.

      1. The pilum actually came in a variety of types ranging from the iconic form to normal looking spears, it might have been an umbrella term for a type of spear. While not well versed in roman history I have the lay opinion that the pilum was the primary weapon of the legionnary, while the gladius was a side-arm. If roman style sword infantry where that effective, we would likely see it crop up more than one time in history.

        1. Infantry fighting with swords from behind shield walls did crop up a lot. It was something you saw in a lot of places. What made the Romans special was the combination of a lot of separate factors, with their swords being probably the least special element of the package.

  10. What were the political motivations for the Roman conquest of Dacia? From what I have read Claudius conquered Britain to seem more legitimate (having had little experience of ruling and been chosen by the Praetorian Guard rather than the Senate), but I am less aware of the situation during the Dacian Wars, in Trajan’s time

    1. There were 2 motivations. The first was that Dacia was coalescing into a kingdom and was not friendly towards Rome. The Dacians raided modern day Bulgaria and tried to convince other populations from Ukraine to do the same. The second was that Dacia had some good gold and silver mines which were turning increasing output while the Roman mines in Spain and Macedon were declining. The Dacians used this gold to hire Greek and Roman engineers and fortify their hiltop / mountain top fortresses, produce more weapons, etc. The Romans conquered Dacia and then stepped up the gold production by an order of magnitude. The mines probably declined and the Romand abandoned the province after about 140 years.

  11. >1. Because it doesn’t fit anywhere else, I want to make a rather long note here. There is an odd tendency which I find quite frustrating, in which military concepts, unit designations and terminology from other languages are all translated into English when used, except for German terms.

    I think we have a case of ‘pot kettle black!

    >In the Roman case, for a completed defense, the outer most defense was the fossa or ditch; (…). The earth excavated to make the fossa was then piled inside of it to make a raised earthwork rampart the Romans called the agger. Finally, on top of the agger, the Romans would place the valli (‘stakes) they carried to make the vallum.

    You happily use latin terms all the time, including for military terms. I don’t think it’s clear these were all notable achievements. The very elaborate way to make your bed – yes, but not the individual components. But you don’t even say what the latin word for a “fort” was!

    Side note: in modern Polish, we have:
    fosa – moat,
    pal – a big wooden stake dug into the ground, usually supporting a structure
    mur – a brick or stone wall, typically outdoors

    1. I think mur (and as someone up in the comments mentiones dutch: muur; german: Mauer) is more as a case in favor of a common Indo-European source for the word.

      1. According to one dictionary it’s a borrowing from German, and so ultimately from Latin. I can’t vouch for the dictionary’s veracity on German etymology, but many such technical terms in the Polish language come from German.

        1. I’m not sure about “mur” specifically, but German is not a Romance language, so most German and Latin cognates reflect a common Indo-European heritage, not a transmission from Latin to German.

          1. That is not as cut and dried as one may think. German has a *considerable* number of loan words from Latin, not all of which got borrowed during the Renaissance and later period when the ancient world was considered the coolest thing ever.
            Add to that a number of words from French, during the 200 or so years when that was Europe’s dominant language (well, French and Spanish for the first of those two centuries.

            Distinguishing IE cognates from a loan word that entered the language in the 3rd century CE isn’t a trivial exercise.

            Mauer specifically derives from Middle High German “mure”, Old High German “mura”, which is usually considered a loan word from Latin, same as “Wall”

    2. Also, Polish has the word “wał” (pronounced: vau) which means an earth bank. Quite possibly inspired by valli / vallum, the latin word for the stakes at the top of the earth bank / agger.

    3. I also wonder about etymological connections between ‘valli’ and the proto-Germanic prefix used to designate Romanish-peopled places all along the old frontier (Wallachia, Walsch-Tirol, Wallonia, Wales, etc). It’s very common globally for people to invent and ethnonym for foreigners based on one prominent habit; does the Legionaries’ insistence on valli all the time echo into modern national identities?

    4. I think Bret’s point was that we often call the German military in WW1 and WW2 by the German words even though there was nothing especially remarkable about their existence and the English translation would be equally useful.

      For example, we usually call the German WW2 airforce the Luftwaffe (literally “air weapon”). While the Luftwaffe itself might be interesting for a lot of reasons, the existence of an air force as a military formation is hardly novel and the term “German air force” would be a fine description of it. It’s not as though the Luftwaffe is a formation that has no parallel in other countries that would be descriptive. Bret points out that we generally do not call the formations of other nations by their language but generally translate (obviously, exceptions exist). The fact that we often refer to them by their original name suggests we hold them with a special awe which Bret suggests is problematic.

      In this case, Bret is teaching us about an ancient civilization and providing for our interest what the Romans called the things. For most of the article, he just calls them ditches. But explaining that the Latin word for ditch is fossa is both interesting to non-latin speakers but also helpful to understand why the defensive structure in Africa would be called the Fossatum Africae.

      In response to your other point though, I think he also makes it clear though that this system was notable and somewhat novel. He cited all the ancient authors who were impressed with it. All this is to say I think there is a big difference between teaching us the latin word for “ditch” and always referring to the WW2 German military as the Wehrmacht while referring the forces of other ww2 belligerents in English.

      1. I agree it’s interesting to know, and disagree he only uses it the first time. Not just this blog post. Scutum, pilum, gladius, lorica segmentata, auxillia, hoplite and other Greek terms. It’s not like Greeks seemed to use many different kinds of troops or combined arms. In the covid article he made a point that Greeks named their troops after the type of shield they carried, but other kinds of Greek troops are hardly ever discussed, here or elsewhere.

        Vallum – 10 occurences in the article, I’m not counting the plural,
        agger – 5,
        fossa – 3 (not counting plural etc.)

        I exclude ‘palisade’ because it seems to be a common enough word in the English dictionary, but someone more pedantic might say a “wall” would completely suffice instead, because the article makes it clear they only built one kind of fort wall until forts started becoming more permanent. In any case a palisade on an earth bank was a common feature in *bronze* age hill forts.

        1. Scutum, pilum, gladius, lorica segmentata, and hoplite are all English loanwords. Some of their meanings have even changed from the original Latin in subtle ways: In Latin, “gladius” just means “sword” (of any kind), but in English, “gladius” refers to a specific type of sword. Of all the words you listed, only “auxillia” seems like a foreign term used unnecessarily, in that you could probably replace it with “auxiliary” and lose no meaning, in the same way that you could replace “Luftwaffe” with “German air force” and lose no meaning.

          So far as “fossa” versus “ditch,” Bret uses “fossa” three times to explain its meaning and “ditch” *fifteen times*, so it’s clear which one of these words is the standard and which one is a translation provided as an additional fun fact. There is a significant difference between someone bringing up “the Luftwaffe (literally ‘air weapon’)” and then going on to refer to the organization as the Luftwaffe for the entire article, as opposed to bringing up “a ditch (‘fossa’ in Latin)” and then going on to refer to them as ditches for the entire article.

          The only Latin term Bret doesn’t merely *mention* but actually uses in place of its English equivalent is “vallum,” where it’s clear in context he’s making a loanword out of it to refer to a Roman palisade, in contrast to other palisades. There’s a whole section of the article about what made the vallum special compared to other palisades.

          To say nothing of the fact that Latin words are easy for English speakers to say. “Vallum” and “fossa” sound like normal words and roll off the tongue better than “Roman palisade” and “Roman ditch,” especially since the latter you’d probably want to specify further with “Roman legion ditch” to distinguish it from ditches dug by, like, Roman farmers and stuff. Vallum and fossa are just shorter words. “Auftragstaktik” sounds *much* worse to an English speaker as compared to its translation of “mission tactics” and I don’t even know what the fuck sound that weird B thing in “Stoßtruppen” is supposed to make.

          1. That weird B thing is effectively a double-s. “Stoßtruppen” should be read as “Stosstruppen,” give or take a little bit of pronunciation.

            More generally, there are two main reasons to use a foreign word for a concept in history.

            1) Because the foreigners did something unusual or special, and you wish to distinguish their way of doing the thing from just any way of doing it. Thus “vallum” instead of “palisade,” because the Romans had specific ways of designing a palisade that were different from other kinds of palisades the reader may be familiar with.


            2) Because one needs a compact name for the thing one is talking about, that calls attention to and avoids ambiguity when referring to the thing. Thus “Luftwaffe” instead of “German air force.” It’s shorter, slightly more compact, and importantly does not have any risk of being confused with the Royal Air Force of the British (routinely called the RAF and not just “the British air force”) or the American air arm (now called the Air Force, then called the Army Air Corps).

            It wouldn’t be impossible to keep track of a paragraph in which one talks about how the German air force fought the British air force and did very well against strategic bombing attacks by the American air force, using “[adjective] air force” as a subject, object, or other noun in each sentence one or more times. But it wouldn’t necessarily be good writing when one can instead call these three forces the “Luftwaffe,” “RAF,” and “Army Air Corps.”

          2. “Royal Air Force” and “Army Air Corps” aren’t translated to English for the obvious reason that they are already English words. The convention for every foreign language except German is to translate the name into English, which is why you’ve seen the acronym “IJN” before, but are so unfamiliar with the Dai-Nippon Teikoku Rikugun that you didn’t even realize that it isn’t the correct translation for the IJN until I told you.

            And between the Nazi air force, the Soviet air force, and the free French air force, can you guess which one’s Wikipedia page isn’t in English?

          3. I think you both have decent points here, but this is hardly unique. People might translate to IJN, but other names and terms like kido butai, mountain, chutai, kamikaze, katana, shogun, etc. are often kept in Japanese. Also cataphract, zhuge nu, name a couple random examples from all over the world that come to mind first. Sometimes it help, sometimes it binders, and often it’s probably simple habit.

          4. The argument isn’t about whether or not English ever uses loanwords from other languages. Obviously it does. The argument is about whether Bret is being hypocritical for using Latin terms after denouncing the broad refusal to translate German terms in his WW1 articles, and the answer is no, he is not, the way in which he uses the Latin terms is clearly consistent with the way foreign languages are generally treated by English speakers, where anything with a direct translation is translated (like the IJN) and only concepts that don’t have a direct translation are made into loanwords (like “katana,” describing a specific type of sword not found in the west, or “shogun,” a unique position to the political situation of feudal Japan). Bret uses Latin terms the same way, and is not being hypocritical when he criticizes the field in general for being pointlessly reverent with the German language.

            And this isn’t just some random nitpicking. This is part of the general obsession with alleged German military superiority in the first half of the 20th century, an obsession which smuggles fascist sympathies into what many people assume is a grounded historical argument, but which is clearly wrong when you stop to think about it, like, at all: Germany did not win a single major conflict during the era for which they are lionized as military experts. When Bret says that German isn’t some kind of Holy Language of War and shouldn’t receive special treatment, he’s making an important point that shouldn’t be both sides’d away.

        2. Comment not showing up, I assume it got auto-moderated because I was swearing at the German language at one point, trying again.

          There’s a huge difference between bringing up “the Luftwaffe (literally ‘air weapon’)” and referring to the organization as the Luftwaffe for an entire article as opposed to bringing up “an encircling ditch (in Latin, fossa)” and referring to the construction as a ditch for the entire article. In one, the foreign term is given priority over an English translation. In the other, the foreign term is offered as a fun fact but the English term is used preferentially.

          Which brings us to “gladius,” “scutum,” “agger,” etc. These are all English words. You can find them in English language dictionaries (yes, including agger, look it up). They were originally Latin words, but in English they are loanwords with slightly different meanings. In Latin, for example, “gladius” refers to any kind of sword. In English, “gladius” refers to a specific type of sword.

          Bret makes a loanword out of “vallum” specifically in this article, for reasons which are obvious in context. Just like the Roman word for “sword” got adopted into English to refer to a specific type of sword associated with Rome, Bret uses the Roman word for “palisade” to denote a Roman palisade, which he contrasts at length with other palisades.

          You will not find “auftragstaktik” in English dictionaries, because saying it is hard on English speakers and the translation of “mission tactics” is sufficient to fully describe the idea.

      2. Ah, that also explains the use of the term “fossae” for linear troughs or striations on various solar system bodies.

        1. Yes, that was due to the Roman invasion of Mars in 328 AD, which I’m hoping will be covered in part 5 of this series.

  12. I’ve been listening to the History of Rome podcast and it said Trajan conquered Dacia in part to get access to their highly productive gold mines. So I would have thought conquering Dacia was a good idea since the mines could easily pay for the added cost of defending the extra territory. You suggest otherwise–what am I missing here?

    Also: I recently started reading this blog and absolutely love it! I never liked history before, but now I’m listening to history podcasts for fun, so, thanks I guess!

      1. Hear, hear!

        Back in primary school we were taught in the way Terry Pratchett ridiculed as “dates, kings and battles”. At the end of secondary school, I decided to take extra history classes in preparation for the final exams. It was eye-opening, because the teacher made us work with source material (short and translated), told us what happened and then ASKED US WHY. She would also split us into factions and had us make a case for our side (I was assigned to Sparta in Sparta vs Athens). And having source material was a much bigger deal back then when broadband internet was only starting to become available. No search engines. No youtube. Try a few hours in a library instead.

        There’s simply no time for that in typical history classes, especially if your education system values memorizing facts over critical thinking and acquiring skills. Even memorizing those stupid dates is easier if you think about history as processes.

    1. As for the conquest thing… Well, according to Wikipedia, the Dacian gold mines were played out by 215 AD. Since the Romans didn’t lose Dacia until after that time, it’s quite possible that the place was profitable to secure and defend… until the gold mines ran out. And then the Crisis of the Third Century hit. And by the time that was over, the Romans had already lost Dacia, and now there weren’t any gold mines to make it profitable for Diocletian or his successors to try and reconquer the place.

  13. The Romans were nothing is not organized and systemic. That was, IMO their real advantage and what won them an empire. They were organized, disciplined AND also innovative. They saw a Good Idea they grabbed it.

    1. Such a contrast with the modern Italian stereotype. Smartly dressed, stylish, good at cooking, art and architecture, but undisciplined and lazy. And the phrase “italian strike” means doing the bare minimum required at your job, but zealously following all rules and regulations.

    2. Nobody expects the Roman Legions! Our chief weapon is organization…organization and discipline. Our two weapons are discipline and organization…and innovation. Our *three* weapons are organization, discipline, innovation…and an almost fanatical devotion to the Emperor. Our *four*…no…*Amongst* our weapons…I’ll come in again.

      1. Going by Bret’s past comments, and Mary Beard’s _SPQR_, the chief weapons were organization, discipline, and co-opting subject people as more soldiers.

        1. Romans chief weapon and source for their endless manpower was that subject people could and did become Romans with full citizenship rights. This also contributed to innovation as new Romans brought their technology and ideas with them.

  14. It would seem that the Romans originally learned their camp-building habits from Procrustes, not from Pyrrhus.

  15. Hi, I am a civil servant in a small town in Galicia, NW Spain. In this town (Negreira; not my hometown, I am from Ferrol, farther to the North) there is a place known as the Castro de Cornado. In 1956, USAF planes made complete maps of the region, using aerial photos. The “Castro” has the shape of a playing card, so people round here think it is probably a roman camp, not a castro properly.

    The following links show the photos from the “American overflight”, as it is known. The text is in Spanish, sorry. Based on the images, what do you think about it?

    Thank you for this wonderful blog, by the way.

  16. Wał (bank) is from Latin via German. Wał (shafr) is slavic. They bith descend from the same PIE root, meaning “to turn in circles” (which also gives waltz). Not sure why how Latin would get “vallum” from that, maybe because stakes are supposed to be rounded, so they are “shafts” in a sense.

  17. Many comments later, my edit suggestions have likely been mentioned by others, but nevertheless, here they are:
    would plave the valli > would place
    range from his planned works > [what does this mean? I cannot follow/?]
    term for both the ROman frontier > Roman
    a fairly remarkably example > remarkable
    a mostly (but not entirely) stone walls> wall [or delete a]
    Hadrian’s walls is unusual > either “walls are” OR “walls are an unusual [formation? fortification?]”
    the Crisis, with legions > [delete the word with]
    motivated in no small by the > no small part by the
    era and we’ll get > era [insert comma] and

  18. Next time, we’ll actually begin to turn to what I suspect you all had in mind when I started writing this

    Fwiw, I had expected—and hoped!—to read about the intersection between Roman imperial strategy and fortification doctrine, and I am quite satisfied! No shame on the castle-fans but this post is my jam in particular.

    1. With castles, as a rule we have a very good understanding of why they were built and how they fit into the overall structure of medieval European feudalism/vassalage/manorialism.* The details of how they were built are interesting, but no more or less so than the design of other fortifications at other times and places.

      With Roman military fortifications, understanding the ‘why’ of the design is a more pressing exercise, because it ties into our general understanding of how the Roman Empire related to its own borders and strategic posture. Which is a question still coming up in contemporary political discussions today!

      *(With a nod to Dr. Devereaux’s comments on the subject, ‘manorialism’ is a word for the economic system that governed how European medieval peasants mostly related to their aristocratic overlords, ‘vassalage’ is a word for the political system that governed how the aristocratic overlords mostly related to each other, and ‘feudalism’ is a loosely defined word for the entire medieval European social order that often encompasses both without properly discussing important parts of the system, so I’m using all three words at once)

      1. That is a very logical specification of terminology, but, sadly, I don’t know of any discursive community where every participant consistently uses the words that. Also, a legal scholar would note that the distinction between economic and political systems is foreign to the middle ages. (A post-structuralist legal scholar, which is what I used to fancy myself, would transvalue and collapse the dichotomy for all time.)

        1. I drew manorialism/vassalage as terms directly from my medievalist colleagues.

          The point is not strictly a difference in legal vs. political, but in how the relationships that structure interactions between aristocrats (vassalage) are not the same as the relationships that structure interactions between the peasantry and those aristocrats (manorialism), though since the peasantry makes up the overwhelming share of economic production and a smaller but still overwhelming share of consumption, the latter has a more pronounced economic impact than the former.

        2. But a historical scholar would note that the term and concept of ‘feudalism’ was foreign to the middle ages too; seems to get started in the 1700s. I’m not a historian, but I would guess concrete terms used at the time would map to ‘liege lord’, ‘vassal’, ‘fief’ and related duties; also ‘manor’, ‘lord of the manor’, ‘serf’, and those duties. Possibly ‘vassalage’ — certainly its inverse, ‘lordship’ — but I’d guess not ‘manorialism’, that being another later label slapped onto what they would have seen as “simply how things are”.

          And as for how modern non-historians use ‘feudalism’, my observation is that it’s often used synonymously with “some form of titled aristocrats exist”.

          1. Frederic Maitland (as I recall) used to say jokingly that feudalism was invented in the nineteenth century.

          2. The relationship of the peasant to his lord looked a lot more like the lord’s to his overlord from outside the era.

          3. The contemporary people likely called it “Some fight, others pray, still others work. The way it has always been.”

  19. The Romans (especially the Imperial Romans) had, if not made a science of war, had made extensive and intensive study of it.
    As noted by our host, they were basically “at war” for the entirety of the pre-Imperial period, and for most of the Imperial period.

  20. “I was treating marching as requiring time and effort; and building a fortress as requiring time and effort. Which on the face of it suggests that reducing the time per day spent building would allow an increase in time per day spent marching.”

    OTOH, different muscles would seem to be involved?

    1. I think anyone who has tried it would agree that working 8 (or 12) hours at a series of different physical tasks is much less difficult–and much less likely to produce repetitive stress injuries–than working the same amount of time at one repetitive task. Hunting in the morning, fishing in the afternoon, etc.

  21. Regarding the Romans being very sensitive to raids, it pays to recall that the Roman soldier was at his peak when fully armoured, properly equipped and properly formed. The same soldier would be at something of a nadir if suddenly obliged to fight without armour, and as a mob of individuals versus another mob of, say, Pannonians.

    Yes, I know it only takes a minute to put on a mail shirt (segmentata, being laced, takes a bit longer). If the enemy is already *in* the camp, rather than chopping through the palisade, you may not have that minute.

Leave a Reply