THE EXPANSION OF ROMAN DOMINION 105 where his armies were destroyed by the Parthians and he himself perished. A breach developed and widened between Caesar and Pompey, who now saw the man whom he had regarded as a useful assistant growing into a dangerous rival. In Caesar's absence the Senatorial party and Pompey were more and more drawn together by their common fear of Caesar. Caesar's governorship terminated nine months before he could again be elected to the consulship. But also there was no means of filling up the governorship, which he p ar ty would naturally continue to hold until a new Intrigues, appointment could be made. The optimates attempted by a technical device to compel Caesar to return to Rome before the consular election. This would have placed him at their mercy. Finally, when Caesar found that unless he could dictate his own terms at the head of his own troops his destruction was certain, he set the law at defiance and marched his legions across the Rubicon, the stream which was the boundary of his province, into Italy proper. Rome lay at his mercy, but Pompey hurried across the Adriatic and summoned the provincial armies to crush the 1 enemy of the republic' In the war which Triumph of followed, Caesar overthrew Pompey at the battle Caesar, 48 B.C. of Pharsalia. The defeated general fled to Egypt whence he still hoped to make head against his rival, but even as he stepped on shore he was slain by the dagger of an assassin. When Caesar had marched on Rome, and Pompey had with- drawn across the Adriatic, Caesar had thought it best, before starting on his campaign against Pompey, to make a swift descent on Spain, which was quickly brought into submission. Now though Pompey w r as slain, the Pompeians rallied in Africa. Pharnaces, son of Mithridates, was making trouble in Asia, and insurrections were threatening in all quarters. Caesar had pursued his rival to Egypt only to learn of his assassination. Delayed there for a time, he marched against Pharnaces whom he crushed. Thence he hurried back to Italy where his com- bined vigour and leniency rapidly quelled the threatening dis- turbance. Then he crossed to Africa, where he utterly shattered
