Auxiliary units
Auxiliary soldiers were organised in infantry units, cohorts (singular
cohors, plural cohortes, abbreviated to coh)
and cavalry units, alae (singular ala). Infantry
units could also sometimes include a cavalry element (cohors
equitata), sometimes described as ‘part-mounted’
regiments. There were two sizes of both cohors and ala,
quingenary (quingenaria) and milliary (milliaria),
the former with a nominal strength of 500 men, the latter with a
nominal strength of 1,000 men, although in practice these figures
are different.
The main infantry subdivision of the cohort was the centuria containing
80 men, itself divided into 10 sections (contubernia).
The term centuria was often symbolised by an abbbreviation
resembling a 7. The main subdivision of the ala or of the
cavalry contingent in a cohors equitata was the turma
probably consisting of 32 cavalrymen.
The table summarises the theoretical composition of these different
units.
Summary table
| Unit |
Subunit |
No. of subunits
|
Number of men per
subunit |
Total no. of men |
| Ala milliaria
|
turma |
24 |
32 |
768 |
| Ala |
turma |
16 |
32 |
512 |
| Cohors milliaria
equitata |
centuria &
turma |
18 (10 centuriae,
8 turmae) |
80 and 32 |
800+256 |
| Cohors milliaria |
centuria |
10 |
80 |
800 |
| Cohors
quingenaria equitata |
centuria &
turma |
9 (5 centuriae,
4 turmae) |
80 and 32 |
480+128 |
| Cohors quingenaria |
centuria |
5 |
80 |
480 |
| Legion |
cohors + centuria
|
10 cohortes,
each of six centuriae (1st cohort of double strength)
|
80 |
c.5000 |
|
The numbers, size and type of barrack blocks are a guide to the
garrisons that occupied forts, along with other evidence such as
inscriptions. At Wallsend for example the eight barrack blocks correspond
well to the requirements of a cohors quingenaria equitata,
of 480 men and 120 cavalry, six
barracks housing the infantry and two the cavalry. In many cases
however the numbers and size of barrack blocks do not fit the standard
pattern, suggesting that parts of several units may have been brigaded
together. Individual units were perhaps in any case only rarely
at their full theoretical strength. 154,
the strength report of the first cohort of Tungrians, a cohors
milliaria peditata illustrates well the potential differences
between the 'paper' strength of a unit and its actual strength.
For further information see The
fort plan and Vindolanda
units and their origins in the exhibition.
|
