During the spring of 43 Octavius advanced against Antony, who was at Mutina (Modena), and defeated him in two battles. He was then appointed Consul, and, finding it for his interest, he deserted the Senate, made friends with Antony, and with him and Lepidus formed (27 November, 43) the SECOND TRIUMVIRATE, assuming full authority to govern and reorganize the state, and to hold office for five years.
The provinces were divided as follows: Lepidus was to have Spain and Gallia Narbonensis; Antony, the rest of Gaul beyond the Alps and Gallia Cisalpína; Octavius, Sicily, Sardinia, and Africa. A bloody prescription followed. Among its victims were CICERO, who was surrendered to please Antony, 300 Senators, and 2,000 Equites.
The Triumvirs could now concentrate their energies upon the East, whither BRUTUS and CASSIUS, the murderers of Caesar, had fled. These two had organized in the provinces of the East an army amounting to 80,000 infantry and 20,000 cavalry. They were employed in plundering various towns of Asia Minor, and finally, in the spring of 42, assembled their forces at Sardis preparatory to an invasion of Europe. After marching through Thrace they entered Macedonia, and found Antony and Octavius opposed to them at PHILIPPI, with an army of 120,000 troops. There were two battles at Philippi in November, 42. In the first, Brutus defeated Octavius; but Cassius was defeated by Antony, and, unaware of his colleague's victory, committed suicide. In the second battle, three weeks later, Brutus was defeated by the united armies of the Triumvirs, and, following the example of Cassius, put an end to his life. With Brutus fell the Republic. The absolute ascendency of individuals, which is monarchy, was then established.
The immediate result of Philippi was a fresh arrangement of the Roman world among the Triumvirs. Antony preferred the East, Octavius took Italy and Spain, and Africa fell to Lepidus.
Octavius tried to establish order in Italy, but many obstacles were to be overcome. Sextus Pompeius, who had escaped from Munda, was in command of a strong naval force. He controlled a large part of the Mediterranean, and, by waylaying the corn ships bound for Rome, exposed the city to great danger from famine. Octavius was obliged to raise a fleet and meet this danger. At first he was defeated by Pompey, but later, in 36, in the great sea fight off NAULOCHUS in Sicily, the rebel was overcome. He fled to Asia with a few followers, but was taken prisoner at Milétus by one of the lieutenants of Antony, and put to death.