5. 49—He was ordered to return and lay down his authority by the Roman Senate, headed by Pompey, who was now his enemy. They were the rival champions of the two parties in the state, the people and the patricians, whose quarrels had so long filled Rome with tumult and slaughter. The tribunes in Cæsar’s interest interposed a veto, which the Roman Constitution authorized them to do. The Senate voted to suspend the Constitution, which really terminated the Roman Republic, Jan. 7, B. C. 49. Cæsar at once crossed the river Rubicon, the boundary of his government, and marched his army on Rome. Pompey and the aristocratic party fled in haste, leaving the public treasure behind. In sixty days Cæsar had possession of all Italy. Sicily, Sardinia, and Spain were next conquered from the officers of Pompey, when he returned to Rome, and was created dictator by his party. He treated all his enemies with clemency. Pompey had gone into Greece, 48—where he gathered a large army. Cæsar followed with his veteran legions, and defeated him in the battle of Pharsalia in Thessaly. Pompey fled to Egypt, where he was treacherously slain, to the great indignation of Cæsar, who would shed no blood but in necessary battle. Thus he became sole master of the world. In a conflict with the Egyptians in Alexandria Cæsar set on fire their fleet, he being attended by but few troops, and the conflagration extended to the Alexandrian Library, filled with inestimable treasures of ancient literature, which were destroyed, to the great loss of future generations. Cæsar soon subdued Egypt, 47—defeated Pharnaces, son of Mithridates, and returned to Rome. 46—He soon passed into Africa, where he defeated his enemies. The celebrated Cato, an inflexible enemy of Cæsar, committed suicide rather than submit to him. In Spain he soon after defeated the sons of Pompey, the last of his foes in arms. He rebuilt Carthage and 45—Corinth. He projected many great public works and useful reforms. The whole power of Roman sovereignty 44—was formally conferred on him by the people, when he was suddenly assassinated by a band of senators and certain conspirators, who imagined it possible to restore the ancient Republic. His nephew, Augustus, succeeded him soon after. 43—The eminent Cicero, never a friend to Cæsar, was assassinated by the connivance of Augustus.