Yes Nick,
Good thought, but since a centurion was not commanding 100 men, a ducentenarius would not necessarily be commanding 200.. Maybe he was on double pay?
![[Image: hypocrite.gif]](http://images.fok.nl/s/hypocrite.gif)
But yes, I tend to agree with you.
Nicasie estimates the following unit strengths:
scholae - 500
legiones (comitatenses) - 1000
legiones (limitanei) - 3000
auxilia palatinae - 800
infantry units (limitanei) - 300
cavalry units (limitanei) - 350
Legions
The traditional legion was 6000 strong. Johannes Lydus also mentions this high number (De Mag. I.46). Vegetius mentions two very strong legions of 6000, but he stresses that legions 'in his day, although the name legion still existed, were much smaller in size.' (I.17, II.3). Vegetius' 'old legion' numbered 10 cohorts, the first numbering 1105 infantry and 132 cavalry, the others 555 and 66, totalling 6100 infantry and 726 cavalry (II.6). However, it is generally assumed that if this organisation ever existed, it probably belonged to the early 3rd century.
It was Mommsen who first noticed that old style legions were probably broken up into 6 detachments of a 1000, each of these commanded by one of the 6 tribunes of the old unit. Only the legions of the limitanei were still commanded by
praefecti. Only Nischer proposed that 'new' legions existed of two units of 500, drawn from every border legion, but his theory lacks evidence. However, the
Beatty papyrus mentions detachments of 500 men. One vexillatio consisted of 1000 men from
legio III Gallica and
legio I Illyrica. Another,
legio II Traiana, consisted of two 500-men units. Two vexillationes of
legio III Diocletiana numbered 1100.
Border legions seems to be much larger than field army legions, because they are usually divided over as much as 7 stations.
When in 359 AD 7 legions (including
equites indigenae, two units of
superventores,
praeventores and
comites sagittarii) were trapped at Amida, they numbered 20-25000 men together with the inhabitants and refugees (XIX.2.14). Two of these legions suffered 400 casualties during a sortie (XIX.6.11). If we assume there were 7500 civilians, this hardly allows for more than 1500 per legion, if the garrison was not a legion of 6000 or if there weren't even more civilians than assumed.
All in all, it seems that Late Imperial legions numbered between 1000 and 1200.
Infantry cohorts
During the time of Septimus Severus, a reorganisation apparently resulted in cohorts 550 strong (up from 480), possibly those meant by Vegetius (II.6). But see below.
Ammianus mentions that Julian sent detachments of 300 men from each unit to Constantine (XX.4.2). In 378, Gratian sent detachments of 500 men to storm the position of the
Lentienses (XXXI.10.13). Also in 378, Valens sent detachments of 300 from each legion to meet the Goths at Adrianople (XXXI.11.2).
It is thought that some of these detachments never returned to their parent unit but retained the original name (hence the repetition of such names in the
Notitia Dignitatum lists). It is also possible that many of the field army units were split up into
iuniores and
seniores, reducing the original strength of these units.
Infantry units mentioned by Ammianus number 300, 500, 800, 1000 and 1500 (XVII.1.4, XVIII.2.11, XXIV.1.6, XIV.1.2, XXIV.6.4, XXV.6.13-15, XXV.7.3).
Johannes Lydus mentioned
cohortes of 300 and
vexillationes of 500 (De Mag. I.46).
Cavalry units
The old style
alae numbered 500 and seem to have remained that way. On paper at least. On the basis on the
Beatty papyri, Duncan Jones calculated that around 300 AD in the Thebaid (Egypt), a unit of
equites was 121 strong, an
ala 116 and a
cohors 164. These may not have been complete units, or else very much understrength.
Nothing much is known about cavalry unit strengths. The
ala III Assyriorum was organized in old-style 11
turmae, giving it a possible strength of 350 (ChLA XVIII 660). Ammianus mentions that the
cataphracti defeated at Strasbourg were 600 strong, which is echoed by Johannes Lydus who says that
alae were that number, and
turmae 300 but also 500 (De Mag. I.46). Ammianus also mentions two
turmae at Amida numbering 700 together (XVIII.8.2). Procopius has various sizes, between 200 and 800 strong (800: Bella VI.5.1, VI.7.25-6). Some units are larger, between 1000 and 1500, but it is unclear if these are units grouped together, or maybe allied forces (1500: Bella V.27.22-3 and VII.34.42). Maurikios mentions cavalry units should be between 300 and 400, but in any case not less than 200 and not above 400; if understrength, they should be combined.
Finally, the
Anglo-Saxon Chronicle mentions that in a battle in 457 AD, '4 units' of Britons were destroyed, while another version of the text mentions a number of 4000. (ASC.
Laud Chronicle year 456,
Parker Chronicle year 457).
Two main conclusions can be drawn of Late Roman units (Nicasie):
a) in practise, the actual number of troops fielded will have been lower than the paper strengths.
b) it seems possible that Late Roman units did not have fixed establishment strengths at all, but varied between a certain minimum and maximum according to need.
hock: