Page:The age of Justinian and Theodora (Volume 1).djvu/191

 Anastasius, at a distance of only forty miles from the capital, we shall need no further evidence that the Byzantines exercised no more than a shadow of political supremacy in these regions. But an exception to the foregoing conditions was generally experienced by the Romans on their eastern frontier, where the Parthian or Persian power was often able to meet them with a civil and military organization equal to their own.

The elaborate scheme for the defence of the Empire against its restless and reckless foes was brought to perfection under Diocletian and Constantine. Armies and fleets judiciously posted were always ready to repel an attack or to carry offensive operations into an enemy's country. A chain of muniments guarded the frontiers in every locality where an assault could be feared. Forts and fortified camps sufficiently garrisoned lined every barrier, natural or artificial, at measured distances. Suitable war vessels floated on the great circumscribing waterways; and where these were deficient their place was supplied by walls of masonry, by trenches, embankments, and pallisades, or even by heterogeneous obstructions formed of felled trees with their branches entangled one with the other. Border lands were*