Their strength was proportioned by Justinian to the danger of their situation.

A ditch and palisade might be sufficient to resist the artless force of the cavalry of Scythia; but more elaborate works were required to sustain a regular siege against the arms and treasures of the great king.

His skilful engineers understood the methods of conducting deep mines, and of raising platforms to the level of the rampart: he shook the strongest battlements with his military engines, and sometimes advanced to the assault with a line of movable turrets on the backs of elephants.

In the great cities of the East, the disadvantage of space, perhaps of position, was compensated by the zeal of the people, who seconded the garrison in the defence of their country and religion; and the fabulous promise of the Son of God, that Edessa should never be taken, filled the citizens with valiant confidence, and chilled the besiegers with doubt and dismay.

[132] The subordinate towns of Armenia and Mesopotamia were diligently strengthened, and the posts which appeared to have any command of ground or water were occupied by numerous forts, substantially built of stone, or more hastily erected with the obvious materials of earth and brick.