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

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The Roman A rmy
ing the third cen tu ry, t h o u gh wh en Severus placed a newly ra i s ed legi on , I I
Parthica, at Alba, a mere 20 miles from Rome, it is debatable whether he needed
it to rush to the war zone or to protect himself. It was perhaps a combination of
these factors , t h o u gh moving the legi on from Rome to the Rhine or Danu be
would probably take longer than it would to shuttle troops along the frontiers
to form a campaign army. This was the time-honored method of assembling an
army for a war, by taking units from more peaceful zones and then either sending
them back to their bases when the war was concluded or on occasion housing
them in new forts in the territory just fought over. The procedure was dangerous
in that it left other areas vu l n era bl e , and there was an incre a s i n gly
obvious need for frontier defenders who remained where they were while the
field armies dealt with the major problems. Constantine put this into practice,
and at some unknown date the comitatenses came into being, consisting of cavalry
and infantry, and new units called auxilia. These last units were raised either
by Constantine or his father, probably from the Rhineland. They were all
infantry units and had nothing to do with the old-style auxiliary units (Southern
and Di xon , 1 9 9 6 ) . The cava l ry and infantry el em ents of the field arm i e s
were placed under two newly created commanders called magister equitum and
m a gi s ter ped i tu m . None of the m a gi s tri of Con s t a n ti n e’s rei gn are known , s o
t h eir previous careers , ra n k , and status can on ly be esti m a ted . Within a short
time there were also regional field armies, since one mobile army under the emperor
was not sufficient to keep the peace all over the Empire.
With the cre a ti on of the field arm i e s , t h ere were ch a n ges to the fron ti er
armies, possibly brought about in Constantine’s reign (van Berchem, 1952). A
l aw dated to ad 325 distinguishes bet ween three classes of troop s : the co m itatenses,
which were the highest ranking, then the ripenses, and finally the alares
et cohortales. There are clear distinctions between the field army (comitatenses),
and the fron ti er armies con s i s ting of ri pen se s ( s om etimes ren dered in other
documents as riparienses) and the old-style alae and cohorts. The term ripenses
covers all the higher-grade frontier troops, whether they are legions or cavalry
units. Mounted units called vexillationes, probably about 500 strong, had been
s t a ti on ed on the fron ti ers perhaps after the rei gn of G a ll i enu s , wh en the legionary
cavalry had been vastly increased in numbers and split off from their
parent legions. They acquired the title vexillationes toward the end of the third
century and are listed in documents as distinct units, with the same rank as legi
on a ri e s . Th ere were va rious other mounted units, s i m p ly label ed e q u i te s , or
cunei equitum. The alares and cohortales of the frontier armies are ranked as the
lowest of all, after legions and cavalry.
The wider term limitanei covers all the frontier troops, of all grades, but it is
not certain when this label was first applied. It is common in the sixth century
but may not have had exactly the same meaning as it did two centuries earlier.
The fron ti er troops of the later Empire are som etimes portrayed as very low