in quota of such troops,
and, when so recruited, the soldiers of this class were required to
serve for twenty-five years. At the expiration of their term they
became Roman citizens, and their descendants ranked as such in the
enjoyment of Roman opportunities. Such forces were not themselves
formed into "legions" under an "eagle"; they served in separate
regiments. Some of them were infantry almost indistinguishable from
the Roman; others were armed in a different manner as to shield,
spear, and sword; others were light skirmishing troops using their
native weapons, such as javelins, slings, and bows. A very large
proportion were cavalry, and whereas a legion possessed only 120 Roman
horsemen, the auxiliary cavalry attached to it would number one or
more regiments of dither 1000 or 500 men each. But it was also part of
the Roman policy to employ such auxiliary troops, not in the region in
which they were raised and among their own people, but elsewhere, and
sometimes even at the opposite extremity of the empire. Thus in
Britain might be found, not only Germans and Batavians, but Spaniards
or Syrians, while in Syria there might be quartered Africans or
Germans, and in Africa troops from the modern Austria. We cannot call
this custom an invariable one, but it was usual, and obviously it was
politic.

[Illustration: FIG. 105.--Imperial Guards.]

To these two co-operating forces--legions and auxiliaries--we must add
the Imperial Guards, twelve regiments of 1000 men each, quartered in
Italy, and generally congregated in a special camp just outside the
gate at the top of the Quirinal and Viminal Hills beyond the modern
railway station. Like other Guards, these were a picked body,
containing many volunteers from Italy itself, while others came from
the most romanized parts of Gaul or elsewhere. They enjoyed many
privileges, wore a more gorgeous armour, served only sixteen years and
received double pay. Frequently it came to be the case that this
particular body of troops was the one which made and unmade emperors,
chiefly under the influence of pecuniary promises or largess. Besides
these, 6000 City Guards were in barracks inside the metropolis for the
protection of the town; 7000 _gendarmerie_, already mentioned, served
as night-watch and fire-brigade, but perhaps scarcely rank as
soldiers. Here and there in the empire there also existed separate
volunteer detachments of various dimensions serving on special duty,
and it wa