Rome, a settlement around a ford on the river Tiber in central Italy conventionally founded in 753 BC, was ruled for a period of 244 years by a monarchical system, initially with sovereigns of Latin and Sabine origin, later by Etruscan kings. The tradition handed down seven kings: Romulus, Numa Pompilius, Tullus Hostilius, Ancus Marcius, Tarquinius Priscus, Servius Tullius and Tarquinius Superbus. In 509 BC, the Romans expelled the last king from their city, favouring a government of the Senate and the People (SPQR) and establishing an oligarchic republic.