Interestingly, Vegetius incorporates a significant degree of Christianity into his text. The recruits into a legion are to ‘swear by God, by Christ and by the Holy Ghost, and by the majesty of the Emperor who, after God, should be the chief object of the love and veneration of mankind.’ This is, of course, a quick theological two-step around the tricky fact that the original Romans were not Christians but pagans, and, in fact, worshipped the Emperors.
Within this, then, is a tacit admission that history cannot be repeated. The legionaries in Vegetius’ day could not swear the same oaths as in Augustus’. The religious context has changed, and some means of squaring the idea of legions and the ‘military oath’ with the effective religion of the Empire has to be found.
The legion, Vegetius says, should be of ten cohorts, the first being a double one. The strength of a cohort is five hundred and fifty-five foot and sixty six horse, giving a total legion of six thousand one hundred foot and seven hundred and twenty six horse. Legions should never be understrength, he claims, but could be made stronger by the addition of extra cohorts.
This, again, is fairly standard ‘Roman’ fare, but it does seem to ignore the peculiarities and practicalities of defending and policing the empire. We know from, for example, the Vindolanda tablets, that cohorts even on an active frontier could muster way below their nominal strength. Vegetius is, it seems focussing on a field army unit, not on frontier forces.
Assuming that the limes of the empire were still garrisoned, we can see that for Vegetius’ legion, frontier work was not in mind. Considering (to take a random example) some of the works on Hadrian’s Wall, the turrets would have, perhaps, accommodated eight men or so, about the size of the basic ‘buddy group’ of the century. This is not a unit that can be concentrated particularly quickly.
This then refocuses attention on one of the more interesting (to wargamers, anyway) controversies of the last few years in Roman Historiography: the ‘Grand Strategy’ of the Empire. Unfortunately the debate has sometimes caused more heat than light and the original work, by Edward Luttwak has not always been treated on its own merits.
Essentially, Luttwak argues that in the early empire, Rome was simply advancing, securing its frontiers by a system of allies and client king agreements, which provided a buffer zone and early warning system for trouble from ‘outside’. Often, however, this buffer zone became itself a problem, and, ultimately, had to be absorbed into the empire proper. Thus the empire expanded, or, eventually, threatened to over-expand.
The solution, implemented by Hadrian, was to stabilize the boundaries and make it clear what was ‘in’ and what was ‘out’ of the empire. There were still outposts beyond, of course, the eyes and ears watching for trouble and the limes themselves, such as Hadrian’s Wall were not isolated fortresses but were defences in depth.
Over time, Luttwak suggests, this system evolved to leave a thinly guarded frontier line, backed up by powerful field armies based on fortresses in rear areas. Thus, Hadrian’s Wall was backed by Chester and York, covering both sides of the Pennines.
The consequence of this shift, according to Luttwak, was that the early empire fought beyond its boundaries, while the later empire fought within them. I think it is fair to say that Luttwak’s analysis has been rather disputed, but also that no-one has come up with any better ideas. Luttwak does not, I think say (as has been attributed to him) this this process was deliberate; it simply arose from the considerations of the context (money, men, resources, etc). Luttwak is a military strategist, not, strictly a classical historian and he wrote ‘The Grand Strategy of the Roman Empire’ in the 1970’s. There are parallels, perhaps, with the Cold War situation in Europe and NATO’s Shield and Sword policy.
Anyway, back to Vegetius. In drawing up his legion for battle, I confess I got a little confused. In his enthusiasm for the old ways, Vegetius divides his legion into principes, the first line of five cohorts, and hastate, the second (as is the Polybius manipular legion). Ten cohorts in total, the full strength of the legion’s infantry. Behind them he claims, cone the light troops, javelins, archers, sligners and so on. Then behind them come the triarii, who wait kneeling until needed. These are not, so far as I can tell, included in the legion’s establishment. I am not quite sure what is going on here. A bit too much backwards looking? An inability to count? A corruption in the text? Any or all of these could be the case, but as I am not using a scholarly edition I cannot tell.
Vegetius then gives a standard sort of account of a legion in battle. The light troops engage first, then the lines of the legion, with strict instructions to the heavy foot not to pursue beaten enemies. This is to be left to the light foot and cavalry (who are on the wings, incidentally).
Vegetius finishes section two of De Re Militari with regulations for promotion within the legion, keeping records and accounts, music and drills.
The latter is, in part, a repeat of things in section one. The most interesting point, perhaps, is about depositions. Half of any donative is to be kept back by the unit, to keep the soldiers loyal. Where your money is, there is your heart, evidently.
As for promotion, Vegetius conceives of a soldier rotating through the cohorts gradually increasing in rank (and pay). So he moved from the tenth to the first cohort, and then back around again at the next level up. One suspects that this was fine in theory, but never really happened that much.
Finally, Vegetius commends the idea of the legion being self-contained, carrying with it all the equipment and men it needs for battle or engineering works such as bridges or siege works. Again, it seems like a nice theory, but I suspect that economies of scale would make it sensible to provide such things at an army level. Still, theorists are for ideals, are they not?