The Late Roman Army

[Robert Vermaat]

We have here a circular argument, since the late roman army was heavier in cavalry, it should be more mobile, as it was more mobile, it was able to defend in depth, like an armour reserve in WWII. Of course, the premise is false, as has been said, cavalry is not faster than infantry at strategical level, any cavalry force had a baggage train that moved at wagon speed. The defnse in depth is also false, I think no ancient author says anything about it (I think) it is a rationalitation of later historians, in fact there are obvious logistical and political reasons, that are mentioned by ancient authors, they are
1) To have armies under closer surveillance, legions spread over the entire limes were easier to revolt, as was so common in the III century
2) Larger armies are easier to feed near large cities

My argument is not that cavalry is more mobile, if you read my argument closely.

Yes, defense in depth in a Roman strategy. Best read Nicasie, Martijn (1997): Twilight of Empire, the Roman Army from the Reign of Diocletian until the Battle of Adrianople, (Thesis Publishers Amsterdam). He makes a very good case for it.

If you follow the development of the field armies, you see where they were needed for. First they were a central reserve in Italy which developed after during the 3d c. the Limes was breached and nothing was there to stop the invaders. This central reserve then gradually evolves into several armies, which then develop into a system of local areas with a Comes in command. At the same time, the frontier zones (especially those under threat) are developed into fronts (such as the Saxon Shore) with a Dux in command.

Each of these areas, behind the Limes, has a small field army. This is true defence in depth, and at the same time very dangerous for these armies were very difficult to control, contrary to your argument.

Yes, cities make it easier to billet troops, but are also a big burden on the populace. And we still can't tell for sure that all the troops were billeted on towns most of the time, even though we know they were some of the time.