The Roman Republic, formed from the old Roman Kingdom in 509 BC, was a nation and then empire that eventually expanded over the entire Mediterranean by conquering less advanced peoples. Rome was the premier economic and military power in all of Europe and Africa by 148 BC, following the defeat of Carthage and the Greek Kingdoms. The Republic and its successor state, the Roman Empire, would maintain this position of local superpower until the collapse of the empire in 317 AD.