Early Rome was located on a fertile plain in central Italy. The geography of Italy, surrounded by seas and mountains, protected it from most invaders. Rome was originally ruled by the Etruscans, but the Romans overthrew their Etruscan king in 509 BC and established a republic with two main social classes - the patricians and plebeians. Over time, the plebeians gained more political rights, including the right to elect tribunes to represent them and veto laws.