Pharsalus (now Phersala), a city of Thes-saly, in Thessaliotis, near the left bank of the Enipeus, and at the foot of Mt. Narthacius. In 455 B. 0. it was unsuccessfully besieged by the Athenian general Myronides. It was for a time in the possession of Antiochus the Great, but was taken by the Roman consul Glabrio in 191. In the time of Pliny Pharsalus was a free state. The ancient city was nearly 4 m. in circuit, and situated on an eminence which was 600 or 700 ft. high, and on three sides was defended by precipices. Leake calls it one of the most important military positions in Greece. - Pharsalus is chiefly celebrated for the battle fought in its territory (called Pharsalia) on Aug. 9, 48 B. O., between Caesar and Pompey. The army of the former, consisting of 22,000 foot and 1,000 horse, was posted on the plain between Pharsalus and the Enipeus; that of the latter, consisting of 45,000 foot and 7,000 horse, was drawn up opposite. Pompey expected with his body of cavalry to turn Caesar's right wing, and thus gain the victory; but his cavalry were unexpectedly assailed by six cohorts of infantry, which Caesar, suspecting the design of the enemy, had stationed on the right as a reserve force.
Pompey's cavalry were put to flight, and, the six cohorts turning his left wing, his troops gave way in every direction. After the rout became general Pompey fled. His camp was stormed about the middle of the day, and the victory was completed by the surrender of four legions, which Caesar took prisoners about nightfall. This battle decided the fate of the Roman world.