ampaign of A.D. 589 was opened by a brilliant stroke on the part
of the Persians, who, through the treachery of a certain Sittas, a petty
officer in the Roman army, made themselves masters of Martyropolis. It
was in vain that Philippicus twice besieged the place; he was unable to
make any impression upon it, and after a time desisted from the attempt.
On the second occasion the garrison was strongly reinforced by the
Persians under Mebodos and Aphraates, who, after defeating Philippicus
in a pitched battle, threw a large body of troops into the town.
Philippicus was upon this deprived of his office, and replaced by
Comentiolus, with Heraclius as second in command. The new leaders,
instead of engaging in the tedious work of a siege, determined on
re-establishing the Roman prestige by a bold counter-attack. They
invaded the Persian territory in force, ravaged the country about
Nisibis, and brought Aphraates to a pitched battle at Sisarbanon,
near that city. Victory seemed at first to incline to the Persians;
Comentiolus was defeated and fled; but Horaclius restored the battle,
and ended by defeating the whole Persian army, and driving it from the
field, with the loss of its commander, who was slain in the thick of the
fight. The next day the Persian camp was taken, and a rich booty fell
into the hands of the conquerors, besides a number of standards. The
remnant of the defeated army found a refuge within the walls of Nisibis.
Later in the year Comentiolus recovered to some extent his tarnished
laurels by the siege and capture of Arbas, whose strong situation in the
immediate vicinity of Martyropolis rendered the position of the Persian
garrison in that city insecure, if not absolutely untenable.

Such was the condition of affairs in the western provinces of the
Persian Empire, when a sudden danger arose in the east, which had
strange and most important consequences. According to the Oriental
writers, Hormisdas had from a just monarch gradually become a tyrant;
under the plea of protecting the poor had grievously oppressed the
rich; through jealousy or fear had put to death no fewer than thirteen
thousand of the upper classes, and had thus completely alienated all
the more powerful part of the nation. Aware of his unpopularity, the
surrounding tribes and peoples commenced a series of aggressions,
plundered the frontier provinces, defeated the detachments sent against
them under commanders who were disaffected, and everywher