war to Macrianus, his Praetorian prefect, whose talents he admired, and
of whose fidelity he did not entertain a suspicion. Macrianus,
however, aspired to the empire, and intentionally brought Valerian into
difficulties, in the hope of disgracing or removing him. His tactics
were successful. The Roman army in Mesopotamia was betrayed into a
situation whence escape was impossible, and where its capitulation was
only a question of time. A bold attempt' made to force a way through the
enemy's lines failed utterly, after which famine and pestilence began
to do their work. In vain did the aged emperor send envoys to propose a
peace, and offer to purchase escape by the payment of an immense sum in
gold. Sapor, confident of victory, refused the overture, and, waiting
patiently till his adversary was at the last gasp, invited him to
a conference, and then treacherously seized his person. The army
surrendered or dispersed. Macrianus, the Praetorian prefect, shortly
assumed the title of emperor, and marched against Gallienus, the son and
colleague of Valerian, who had been left to direct affairs in the West.
But another rival started up in the East. Sapor conceived the idea of
complicating the Roman affairs by himself putting forward a pretender;
and an obscure citizen of Antioch, a certain Miriades or Cyriades, a
refugee in his camp, was invested with the purple, and assumed the title
of Caesar. [PLATE. XIII.]

[Illustration: PLATE 13.]

The blow struck at Edessa laid the whole of Roman Asia open to attack,
and the Persian monarch was not slow to seize the occasion. His troops
crossed the Euphrates in force, and, marching on Antioch, once more
captured that unfortunate town, from which the more prudent citizens had
withdrawn, but where the bulk of the people, not displeased at the turn
of affairs, remained and welcomed the conqueror. Miriades was installed
in power, while Sapor himself, at the head of his irresistible
squadrons, pressed forward, bursting "like a mountain torrent" into
Cilicia and thence into Cappadocia. Tarsus, the birthplace of St. Paul,
at once a famous seat of learning and a great emporium of commerce,
fell; Cilicia Campestris was overrun; and the passes of Taurus, deserted
or weakly defended by the Romans, came into Sapor's hands. Penetrating
through them and entering the champaign country beyond, his bands soon
formed the siege of Caesarea Mazaca, the greatest city of these parts,
estimated, at this time