Just when you think you're nearing the end of a major project you can sometimes find yourself derailed - and rerouted - by a seemingly minor detail. In this case, I'm nearing the end of substantially revised MA thesis-cum-book. I have a draft of just about every chapter, and much of another (the outstanding one), and my hope is there won't be too much left to go on those which are essentially complete.
At present, besides going over the near-complete chapters, I'm in the process of writing the final chapter, which involves sorting through a mountain of data. The book is on the Roman military in the Moesias (Serbia/Bulgaria, essentially), and this final chapter deals with strategic issues, at least with respect to troop numbers and types. Not necessarily horribly complicated stuff - just a lot of guestimating and sorting.
Well, things seemed to progressing fairly well until I came to the point where I started sorting through the respective numbers of infantry and cavalry. That too would seem to be straightforward enough: legions are predominantly infantry (with a handful of cavalry), while auxiliary alae are cavalry and auxiliary cohortes are infantry, mostly. Ignoring the occasional unit of archers (sagittaria, sagittariorum) and heavily-armoured cavalry (catafracta), it happens (as I knew) that you sometimes find these exceptional auxiliary cohorts classed as cohors equitata that are part mounted. Again, fair enough. You also sometimes find auxiliary cohorts that are nearly double-strength, the milliary cohorts or cohors milliaria. Again, straightforward enough.
Where I've been thrown off is the process of checking the names of units I've put together in tables with some names found in some standard/important works, like the book and papers of Matei-Popescu. Well, I've just discovered that he's named what seems like most of the auxiliary cohorts of Moesia Inferior as both equitate and millitary (or occasionally either/or). Somehow, this point had passed me by. I guess since I hadn't been concerned with the nuances just yet - only strictly relevant for my purposes when I'm tabulating and explaining, which is where I am now.
One of the catches with all of this is that my lists have been complied almost exclusively from diplomas (meant to be copies of official documents) - and all these extra bits don't show up. I've done a bit of digging in the other known inscriptions, with more to go, but those extra names aren't coming up. So, as things stand, I've come up with the following set of questions.
When does a unit become equitata or milliaria? It seems unlikely that this was something that happened initially. What constitutes the official title for an auxiliary unit? Is it the title we find on the diplomas issued to eligible soldiers, and perhaps too on the various stamps that we find in fortifications? What is more, how does one decide which part of a name to include on an inscription? To some degree, you can understand the desire to include civium Romanorum or pia fidelis given their association with excellent performance. Who wouldn’t want to honour the deceased with a unit name that contained those elements? On the other hand, if a unit name does not include some of these elements, does that mean we should exclude them, and if not, how do we know about them in the first place? There seem to be an awful lot of milliary and equitate cohorts in Moesia Inferior; with respect to the latter, it almost seems to reach a state whereby almost the entire auxiliary garrison of the province is cavalry based. Would this not be excessive and undesirable? Even more, could the Roman state even afford so many horses? And why Moesia Inferior? Was this a recognition of the unique problems posed by the specific kinds of enemies that we find across the border, so to speak, what with all the Sarmatians and the like with their horse-archers, cataphracts, and so forth?
So, it's time to look through a few hundred inscriptions (thankfully considerably easier than it was 12 years ago when I started this), and to re-read some books and journal articles.