of Europe was evolving feudalism, the Byzantine empire was acquiring an
army and military system scarcely surpassed by any of those of antiquity
and not often equalled up to the most modern times. The _foederati_
disappeared after the time of Justinian, and by A.D. 600 the army had
become at once professional and national. For generations, regiments had
had a corporate existence. Now brigades and divisions also appeared in
war, and, somewhat later, in peace likewise. With the disappearance of
the barbarians, the army became one homogeneous service, minutely
systematized, and generally resembling an army in the modern sense of
the word. The militia of the frontier districts performed efficiently
the service of surveillance, and the field forces of disciplined
regulars were moved and employed in accordance with well-reasoned
principles of war; their maintenance was provided for by a scutage,
levied, in lieu of service, on the central provinces of the empire.
Later, a complete territorial system of recruiting and command was
introduced. Each "theme" (military district) had its own regular
garrison, and furnished a field division of some 5000 picked troopers
for a campaign in any theatre of war. Provision having been made in
peace for a depot system, all weakly men and horses could be left
behind, and local duties handed over to second line troops; thus the
field forces were practically always on a war footing. Beside the
"themes" under their generals, there were certain districts on the
frontiers, called "clissuras," placed under chosen officers, and
specially organized for emergency service. The corps of officers in the
Byzantine army was recruited from the highest classes, and there were
many families (e.g. that from which came the celebrated Nicephorus
Phocas) in which soldiering was the traditional career. The rank and
file were either military settlers or men of the yeoman class, and in
either case had a personal interest in the safety of the theme which
prevented friction between soldiers and civilians. The principal arm
was, of course, cavalry, and infantry was employed only in special
duties. Engineer, train and medical services were maintained in each
theme. Of the ensemble of the Byzantine army it has been said that "the
art of war as it was understood at Constantinople ... was the only
system of real merit existing. No western nation could have afforded
such a training to its officers till the 16th or ... 17th century." The
vitality of such an army remained intact long after the rest of the
empire had begun to decay, and though the old army practically ceased to
exist after the great disaster of Manzikert (1071), the barbarians and
other mercenaries who formed the new service were organized, drilled and
trained to the same pitch of military efficiency. Indeed the greatest
tactical triumph of the Byzantine system (Calavryta, 1079) was won by an
army already largely composed of foreigners. But mercenaries in the end
developed praetorianism, as usual, and at last they actually mutinied,
in the presence of the enemy, for higher pay (Constantinople, 1204).