Zodiac and Late Roman Army Organisation

[Robert Vermaat]

Hi Evan, very interesting!

A few notes:

Now, Pompeius suggests that the Comitatensian Legion, as according to Zozimus, was approximately 1200 strong by AD 400), because the Dalmatian troops were 6000 strong total. But another possiblity, when interpreted, was that it was 5 detatchments of 1200, implying the Legion may have in fact been larger.

Well, if I read him correctly, he gives a number of 1000-1200, which is very much in line with current thinking. He does not speak of these regiments as detachments, so I take it that’s your interpretation? Your mate Pompeius als rightly notes that the strength of these new (smaller) legions cannot be evidenced.

It seems that the Legions were not reduced in size overall, but simply operated in Vexillations. Therefore we cannot determine a definite size of the Legion, because they were divided up in different ways (Thomas Momnensen and Seeck).

This is not what your friend Pompeius has concluded. Legions could and were split up. Indeed, vexillations were split from the original unit, probably never to return, but we have also occasions where legions were split up into 2 smaller units, or into 5: yes, these methods varied. It’s useless to look for a uniform method behind this, as the Roman army did not operate in such a modern manner.

I’ve noticed that your Pompeius failed to see that the system of the Old units and that of the New units (including differing names for units and officers) exited next to another, continuing partly into the 6th or even 7th century. His ‘Old Full legion’ is simply the older legion, later best referred to as the Limitanei legion, whereas the name ‘legion’ itself becomes a much more generic name for ‘regiment’ or ‘unit’.

Ergo Vegetius' number of 6100 infantry and 726 cavalry could indeed be correct.

I think not. Vegetius is still looking back at an earlier age, in which cavalry was still attached to legionary infantry. Following Vegetius in that re-attachment would go back on that development, which is unsupported by any other evidence.

Vegetius, in his second Epistula, details that the term 'Manipulus' replaced the contubernium, but both still served the same function, being about 8-10 men.

To the contrary, Vegetius claims that the contubernium of his day was formerly referred to as a ‘manipulus’.
NB: Both you and Pompeius refer to Vegetius’ contubernium as 8-10 men, but that is contrary to Vegetius, who clearly states that his contubernium counts 10 men. As this is contrary to other evidence of the basic number for a Late Roman unit (being 8), it’s one more reason to think that Vegetius looked at older sources, which he mixed with the reality of his own day, creating a difficult to separate fantasy/reality.

Pompeius has seen that the officer called a Ducenarius, as described by Vegetius, suggests that he commanded 200 men.

Milner has, in my opinion rightly, suggested that Vegetius made a mistake here, in all probability wrongly equating ‘ducenti’ into ‘ducentenarius’. A classic example of a ‘ducentenarios’ however is not known from the military, but from horse-racing, as a horse with two hundred victories (Diocles). As a result we cannot be sure if Vegetius, as he often did, made something up or mentioned the actual number of men under the command of a ducenarius. The word ‘ducentenarius’ as a commander of two hundred men is not known before Bede (8th c.).

[quote="Magister Militum Flavius Aetius" post=301408A Legion could not be divided into cohorts, because it could range between 800 and 1500 men based on the size of the mother unit and the number of Vexillations it was split into.[/quote} I see no reason to conclude that. As cohorts were not restricted to an exact number of men either, there’s no reason to suppose that legions could not be split into a number of cohorts.