Augustus was the founder of the Roman Principate and considered the first Roman emperor, controlling the Roman Empire from 27 BC until his death in AD 14. He was born Gaius Octavius into an old and wealthy equestrian branch of the plebeian gens Octavia. His maternal great-uncle Julius Caesar was assassinated in 44 BC, and Octavius was named in Caesar's will as his adopted son and heir, then known as Octavianus (Anglicized as Octavian). He, Mark Antony, and Marcus Lepidus formed the Second Triumvirate to defeat the assassins of Caesar. Following their victory at the Battle of Philippi, the Triumvirate divided the Roman Republic among themselves and ruled as military dictators. The Triumvirate was eventually torn apart by the competing ambitions of its members. Lepidus was driven into exile and stripped of his position, and Antony committed suicide following his defeat at the Battle of Actium by Octavian in 31 BC.