The Roman Senate was a political institution in ancient Rome founded in 753 BC to advise the kings of Rome. After Lucius Junius Brutus' coup against the Etruscans in 509 BC and the establishment of the Roman Republic, the Senate became the center of the republic, with annually-elected consuls (two per year) being elected to lead the senate. The Senate ruled Rome as an oligarchy, and it was full of corruption due to conflict between rival Roman families or plain greed. Rome was torn apart by civil wars as a result, ending when Julius Caesar took control of Rome as dictator. His adoptive son Octavian founded the Roman Empire in 27 BC, and the Senate was sidelined in decision-making, as the emperors had almost all of the power. The Senate still remained intact, however, and it often clashed with the military and the elite Praetorian Guard to choose emperors of Rome. The senate outlived the Roman Empire and even the Western Roman Empire, existing under barbarian and Byzantine rule, but it vanished between 603 and 630. A senate in the Byzantine Empire's capital of Constantinople still existed, but the old Roman Senate was gone.