Control of the Caesarian party was disputed between Mark Antony and Caesar's nephew Octavian. Octavian wanted revenge for Caesar's death, while Antony favoured reconciliation. Eventually, however, Octavian persuaded Antony to take the field and together they defeated the army of Caesar's assasins Brutus and Cassius at Philippi in 42 BC.
Antony and Octavian agreed to divide effective power between them, Octavian taking the western provinces, and Antony the east, with a smaller third share for their Lepidus. This became known as the Second Triumvirate. Octavian spent the following years building up and consolidating his position in the west. In 38 BC, he launched a determined campaign to capture Sicily from Sextus Pompey, son of Pompey the Great, who had turned the island into a staging ground from which to harrass Rome's grain supplies. It took two years to win and Octavian was then faced with the task of neutralizing Lepidus when the latter attempted to stage a coup against him.
Once Octavian had consolidated his hold on the west he was in a position for a final showdown with Mark Antony. Mark Antony had fallen under the influence of Cleopatra, Queen of Egypt, who was mistrusted by many Romans. The beginning of the end for Antony came in 32 BC, when Octavian drove Antony's supporters from Rome and declared war on Cleopatra. Antony advanced to Actium on the east side of the Adriatic, where the final sea battle was fought on the second of September, 31 BC. After a brief struggle, Antony and Cleopatra fled the scene, yielding outright victory to Octavian. The civil wars ended with their suicide in Egypt the following year. Octavian was now the sole ruler of the Roman world; four years later in 27 BC, he was granted the title of Augustus, becoming the first Roman Emperor.