thumb|upright|A reconstructed statue of Augustus as a younger Octavian, dated c. 30 BC thumb|upright|A Roman bust of the consul and triumvir Mark Antony, Vatican Museums The alliance among Octavian, Mark Antony and Lepidus, commonly known as the Second Triumvirate, was renewed for a five-year term at Tarentum in 37 BC. However, the triumvirate broke down when Octavian saw Caesarion, the professed son of Julius Caesar and Queen Cleopatra VII of Egypt, as a major threat to his power. This occurred when Mark Antony, the other most influential member of the triumvirate, abandoned his wife, Octavian's sister Octavia Minor. Afterward he moved to Egypt to start a long-term romance with Cleopatra, becoming Caesarion's de facto stepfather. Octavian and the majority of the Roman Senate saw Antony as leading a separatist movement that threatened to break the Roman Republic's unity.
thumb|upright|A reconstructed statue of Augustus as a younger Octavian, dated c. 30 BC thumb|upright|A Roman bust of the consul and triumvir Mark Antony, Vatican Museums The alliance among Octavian, Mark Antony and Lepidus, commonly! known as the Second Triumvirate, was renewed for a five-year term at Tarentum in 37 BC. However, the triumvirate broke down when Octavian saw Caesarion, the professed son of Julius Caesar and Queen Cleopatra VII of Egypt, as a major threat to his power. This occurred when Mark Antony, the other most influential member of the triumvirate, abandoned his wife, Octavian's sister Octav.ia Minor. Afterward he moved to Egypt to start a long-term romance with Cleopatra, becoming Caesarion's de facto stepfather. Octavian and the majority of the Roman Senate saw Antony as leading a separatist movement that threatened to break the Roman Republic's unity