According to tradition the ancient city was founded by Romulus (after whom it is named) in 753 BC on the Palatine Hill; as it grew it spread to the other six hills of Rome （Aventine, Caelian, Capitoline, Esquiline, Quirinal, and Viminal）. Rome was ruled by kings until the expulsion of Tarquinius Superbus in 510 BC led to the establishment of the Roman Republic. By the mid 2nd century BC Rome had subdued the whole of Italy and had come to dominate the western Mediterranean and the Hellenistic world in the east, acquiring the first of the overseas possessions that became the Roman Empire. By the time of the empire's fall the city was overshadowed politically by Constantinople, but emerged as the seat of the papacy and as the spiritual capital of Western Christianity. In the 14th and 15th centuries Rome became a centre of the Renaissance. It remained under papal control, forming part of the Papal States, until 1871, when it was made the capital of a unified Italy.