Pressured by his officers, Pompey reluctantly engaged in battle and suffered an overwhelming defeat, ultimately fleeing the camp and his men, disguised as an ordinary citizen.

[9] Caesar then withdrew east into Thessaly, partly to relieve one of his legates from attack by Metellus Scipio's forces arriving from Syria.

Strabo in his Geographica (Γεωγραφικά) mentions both old and new Pharsaloi, and notes that the Thetideion, the temple to Thetis south of Scotoussa, was near both.

In 198 BC, in the Second Macedonian War, Philip V of Macedon sacked Palaepharsalos (Livy, Ab Urbe Condita 32.13.9), but left new Pharsalos untouched.

Many scholars, therefore, unsure of the site of Palaepharsalos, followed Appian (2.75) and located the battle of 48 BC south of the Enipeus or close to Pharsalos (today's Pharsala).

The identification seems to be confirmed by the location of a place misspelled "Palfari" or "Falaphari" shown on a medieval route map of the road just north of Pharsalus.

But Hirtius (if he is the author of the de Bello Alexandrino) also refers to the battle as having taken place at Palaepharsalus, and this name also occurs in Strabo, Frontinus, Eutropius, and Orosius.

[19] The only ancient sources to refer to the battle as being at Pharsalus are a certain calendar known as the Fasti Amiternini and the Greek authors Plutarch, Appian, and Polyaenus.

[28] These all formed a remarkably diverse group, including Gallic and Germanic horsemen alongside all polyglot peoples of the east – namely Greeks, Thracians, and Anatolians from the Balkans and Syrians, Phoenicians and Jews from the Levant.

The two generals deployed their legions in the traditional three lines (triplex acies), with Pompey's right and Caesar's left flanks resting on river Enipeus.

[30] As the stream provided enough protection to that side, Pompey moved almost all of his cavalry, archers, and slingers to the left, to make the most of their numerical strength.

[33] The Pompeian cohorts were arrayed in an unusually thick formation, 10 men deep: their task was just to tie down the enemy foot while Pompey's cavalry, his key to victory, swept through Caesar's flank and rear.

[35][iii] Labienus was entrusted with command of the cavalry charge,[37] while Pompey himself took up a position behind the left wing in order to oversee the course of the battle.

As Caesar's men neared throwing distance, without orders, they stopped to rest and regroup before continuing the charge;[41] Pompey's right and centre line held as the two armies collided.

[citation needed] Pompey lost the will to fight as he watched both cavalry and legions under his command break formation and flee from battle, and he retreated to his camp, leaving the rest of his troops at the centre and right flank to their own devices.

He ordered the garrisoned auxiliaries to defend the camp as he gathered his family, loaded up gold, and threw off his general's cloak to make a quick escape.

[45] Pompey, despairing of the defeat, fled with his advisors overseas to Mytilene and thence to Cilicia where he held a council of war;[46] at the same time, Cato and supporters at Dyrrachium attempted first to hand over command to Marcus Tullius Cicero, who refused, deciding instead to return to Italy.

Until then much of the Roman world outside Italy supported Pompey and his allies due to the extensive list of clients he held in all corners of the Republic.

[citation needed] The battle gives its name to the following artistic, geographical, and business concerns: In Alexandre Dumas' The Three Musketeers, the author makes reference to Caesar's purported order that his men try to cut the faces of their opponents – their vanity supposedly being of more value to them than their lives.