Caesar vs Pompey

In 50 BC, the Senate, led by Pompey, ordered Caesar to disband his army and return to Rome because his term as Proconsul had finished.Moreover, the Senate forbade Caesar to stand for a second consulship in absentia. Caesar thought he would be prosecuted and politically marginalised if he entered Rome without the immunity enjoyed by a Consul or without the power of his army. Pompey accused Caesar of insubordination and treason. On January 10, 49 BC Caesar crossed the Rubicon river (the frontier boundary of Italy) with only one legion and ignited civil war. Upon crossing the Rubicon, Plutarch reports that Caesar quoted the Athenian playwright Menander in Greek, saying ἀνερρίφθω κύβος (let the die be thrown). Suetonius gives the Latin approximation alea iacta est (the die is thrown).The Optimates, including Metellus Scipio and Cato the Younger, fled to the south, having little confidence in the newly raised troops especially since so many cities in northern Italy had voluntarily surrendered. An attempted stand by a consulate legion in Samarium resulted in the consul being handed over by the defenders and the legion surrendering without significant fighting. Despite greatly outnumbering Caesar, who only had his Thirteenth Legion with him, Pompey had no intention of fighting. Caesar pursued Pompey to Brindisium, hoping to capture Pompey before the trapped Senate and their legions could escape.Pompey managed to elude him, sailing out of the harbour before Caesar could break the barricades.
Lacking a naval force since Pompey had already scoured the coasts of all ships for evacuation of his forces, Caesar decided to head for Hispania saying "I set forth to fight an army without a leader, so as later to fight a leader without an army." Leaving Marcus Aemilius Lepidus as prefect of Rome, and the rest of Italy under Mark Antony as tribune, Caesar made an astonishing 27-day route-march to Hispania, rejoining two of his Gallic legions, where he defeated Pompey's lieutenants. He then returned east, to challenge Pompey in Greece where on July 10, 48 BC at Dyrrhachium Caesar barely avoided a catastrophic defeat when the line of fortification was broken. He decisively defeated Pompey, despite Pompey's numerical advantage (nearly twice the number of infantry and considerably more cavalry), at Pharsalus in an exceedingly short engagement in 48 BC.In Rome, Caesar was appointed dictator, with Mark Antony as his Master of the Horse; Caesar resigned this dictatorate after 11 days and was elected to a second term as consul with Publius Servilius Vatia as his colleague.
Cleopatra Before Caesar by artist Jean-Léon Gérôme, 1866
He pursued Pompey to Alexandria, where Pompey was murdered by a former Roman officer serving in the court of King Ptolemy XIII. I got this information athttp://en.wikipedia.org/wiki/Julius_Caesar#Civil_war