Antony had given him much cause. You will remember that Queen Cleopatra whom Cæsar had put on the Egyptian throne beside Ptolemy. Cæsar had fallen in love with her. Antony fell in love with her too. For her sake he divorced and sent back Octavia, his wife, to her brother, Octavius, at Rome. He assumed all the airs of an Eastern despotic ruler, with Cleopatra as his queen. A great many of his own people and friends and servants were disgusted by this. Probably the support that they had given him was not given very whole-heartedly. Certainly Octavius could easily find an excuse for making war on him, for Antony's ideas of government were not at all such as agreed with the Romans' idea of how government should be conducted by a Roman citizen.
The deciding battle between the two was a sea-fight off Actium. Cleopatra was there, but even she does not seem to have fought very bravely for Antony. She turned out of the fight before it was really decided, and fled, with her ships, to Egypt. Her flight probably did decide the result, and Antony, with such ships as could escape, went to Egypt after her. Octavius did not pursue them at once, but a year later he went to Egypt, and, rather than face his coming, Antony and Cleopatra committed suicide.
Octavius victorious
Several years before this, Octavius had dealt with the other man of the Triumvirate, Lepidus. Lepidus, like Antony, seems to have acted just as if he wished Octavius to have a good excuse for getting rid of him, or of his power. He came to Sicily from Africa, apparently at Octavius' bidding; and when he tried, or was accused of trying, to gain possession of Sicily for himself, Octavius replied by defeating his forces, taking Lepidus himself to Italy, and, with more magnanimity than conquerors often show, allowing him to retain his high office of Pontifex Maximus.
He could well afford to be generous, for he was now Master of the World; master as not even his grand-uncle Cæsar, by whom he had been adopted as a son, had been world-master. Cæsar was assassinated in the very year following his election as dictator. Octavius put down his last rival, Antony, at Actium in 31 B.C., and his world-mastery endured until his death in 14 A.D.
I have said that Octavius was a very prudent man. He wished all the old forms of republican government to go on just as they had before. And so they did go on, but Octavius must have known, and everybody else must have known, that they went on just because he allowed them to do so, that he could stop them or alter them at any moment if he pleased, that the government was in form republican—government by persons elected by the people—but that it really was government by one man. And far better it should be so. The other way had been tried and had failed terribly; it had resulted in fearful lawlessness. Now the Pax Romana, that peace of the world under the controlling power of Rome, really did begin to be something like a real fact. It had been very much of a fiction up to now. Of course there were troubles on the frontier. Those Parthians, who had defeated Antony, had to be dealt with; and they were dealt with, and that disgrace to the Roman arms was wiped out.
I am not sure that the most troublous spot in all the Empire of Rome was not that little kingdom of Judæa (sometimes it was a kingdom, under a petty king like Herod, but oftener it was under a Roman governor who had the title of procurator), which never seems to have been able to rest for long together.