ost accessible passages, to exclude
the ambition of the Persian monarch. [130] The principal source of
the Euphrates descends from the Chalybian mountains, and seems to flow
towards the west and the Euxine: bending to the south-west, the river
passes under the walls of Satala and Melitene, (which were restored
by Justinian as the bulwarks of the Lesser Armenia,) and gradually
approaches the Mediterranean Sea; till at length, repelled by Mount
Taurus, [131] the Euphrates inclines its long and flexible course to
the south-east and the Gulf of Persia. Among the Roman cities beyond the
Euphrates, we distinguish two recent foundations, which were named from
Theodosius, and the relics of the martyrs; and two capitals, Amida and
Edessa, which are celebrated in the history of every age. 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. The eye of Justinian investigated every
spot; and his cruel precautions might attract the war into some lonely
vale, whose peaceful natives, connected by trade and marriage, were
ignorant of national discord and the quarrels of princes. Westward of
the Euphrates, a sandy desert extends above six hundred miles to the Red
Sea. Nature had interposed a vacant solitude between the ambition of two
rival empires; the Arabians, till Mahomet arose, w