Battle of Pharsalus

On 9 August 48 BC, Julius Caesar defeated his great rival Pompey the Great at Pharsalus in Thessaly, in the decisive battle of the Roman civil war. The war had begun in 49 BC when Caesar crossed the Rubicon River with his army and marched on Rome. Pompey and much of the Senate fled to Greece, where Pompey assembled a large army. Pompey had around twice as many soldiers as Caesar and a much stronger cavalry force. His plan was to use his cavalry to sweep around Caesar's right flank. Caesar anticipated this and secretly placed a fourth line of his best infantry behind his cavalry. When Pompey's horsemen charged and pushed back Caesar's cavalry, they ran into these troops, who used their javelins as thrusting spears aimed at the riders. The cavalry panicked and fled, and Caesar's forces then attacked Pompey's army from the flank. Pompey fled to Egypt, where he was murdered on the orders of the young king Ptolemy XIII. The battle made Caesar the master of the Roman world.