The Roman Army: A Social and Institutional History - Karatunov.net

102
The Roman A rmy
isters of their original centuries. Epigraphic evidence attests that the horsemen
were commanded by centurions like the rest of the soldiers, and not by decurions
who were the commanders of all other cavalry. One inscription records an
optio equitum serving in the fifth century of the seventh cohort of legio III Augusta
(CIL VIII 2568, 18), and a tombstone from Lincoln in Britain shows that
the horseman Quintus Cornelius served under the centurion Cassius Martialis.
It cannot be proved wh et h er the e q u i te s l ived in the barracks of the cen tu ri e s
where they were first enrolled or whether they remained on the century records
but were in fact housed all together somewhere in the legionary fortresses.
Apart from the literary evidence of Josephus, there is no further documentation
about the numbers of legionary cavalry until the middle of the third century.
During the reign of Gallienus when the Empire was under threat of disintegra
ti on , the nu m bers of the e q u i tes legionis were va s t ly incre a s ed to 726
h ors em en . This figure derives from the work of Vegetiu s , who says that there
were 66 cavalry in each cohort and 132 in the first cohort (Epitoma Rei Militaris
2 . 6 ) . The functi ons of the legi on a ry cava l ry are not firm ly establ i s h ed at any
time in its ex i s ten ce . It has been su gge s ted that the hors em en were mounted
messengers, but it seems that they trained together as a unit and performed the
same exercises as the ordinary cavalry, using the same weapons. When Hadrian
addressed the troops after their military exercises at Lambaesis in Numidia, he
praised the equites legionis for their javelin throwing, performed while they were
wearing the legionary cuirass (CIL VIII 18042; ILS 2487; 9133–9135).
Al t h o u gh it is known that the legi on a ry cava l ry tra i n ed as a unit and was
grouped together on the march, it is not known if there was an officer in command
of the equites. Some authors have suggested that if there were such an officer,
he would be a centurion, while others favor the optio, mainly because this
is attested on an inscription (CIL VIII 2568). In the third century, when the Emperor
Gall i enus requ i red an arm ed force of great mobi l i ty and speed to de a l
with threats on several different fron t s , he amalga m a ted all types of c ava l ry
from the auxiliary units and from the legions and created a mounted army with
its own commander, called Aureolus. Vegetius says that the legionary cavalry of
the later Empire was divided into turmae and commanded by decurions.
Engineers, Artillerymen, and Other Specialists
In the Imperial Roman army there was no engineer or artillery corps. The engineers
and artillerymen, as well as all other specialist workers, were registered as
m em bers of i n d ivi dual cen tu ri e s . The men who perform ed specialist duti e s
were immunes, who were exempt from fatigues, guard duties, laboring jobs, and
o t h er tasks su ch as latrine cl e a n i n g. Im munes a re first atte s ted in the mids
econd cen tu ry, but the con cept prob a bly dates from a mu ch earl i er peri od .