*Crassus in Syria, 55–53 B. C.* After the assignment of the provinces by the Trebonian Law in 55 B. C., Crassus set out for Syria intending to win military power and prestige by a war against the Parthians, an Asiatic people who, once the subjects of the Persians and Seleucids, had established a kingdom which included the provinces of the Seleucid empire as far west as the Euphrates. Crassus had no real excuse for opening hostilities, but the Parthians were a potentially dangerous neighbor and a campaign against them gave promise of profit and glory. Accordingly, in 54 B. C., Crassus made a short incursion into Mesopotamia and then withdrew to Syria. The next year he again crossed the Euphrates, intending to penetrate deeply into the enemy’s country. But he had underestimated the strength of the Parthians and the difficulties of desert warfare. In the Mesopotamian desert near Carrhae his troops were surrounded and cut to pieces by the Parthian horsemen; Crassus himself was enticed into a conference and treacherously slain, and only a small remnant of his force escaped (53 B. C.). But the Parthians were slow in following up their advantage and Crassus’ quaestor, Cassius Longinus, was able to hold Syria. Still Roman prestige in the East had received a severe blow and for the next three centuries the Romans found the Parthians dangerous neighbors. The death of Crassus tended to hasten a crisis in Rome for it brought into sharp conflict the incompatible ambitions of Pompey and Caesar, whose estrangement had already begun with the death of Pompey’s wife Julia in 54 B. C.