The Roman Republic
In the earliest period Rome had been ruled by a series of kings. Following the expulsion of the last of these, Tarquin the Proud, in 509 BC, Rome became a Republic. Under this system supreme power was shared by two senior magistrates, the Consuls, elected annually. However, the effective governing body of the state was the Senate, an assembly of representatives of all the most respected and powerful (or patrician) families in Rome. The mass of ordinary people, the plebeians (plebs), fought to protect their interests, especially in the areas of debt and land reform, through two other magistrates called the Tribunes.
During the Republic, Rome began to expand her territory through treaty, trade and war with neighbouring Latin-speaking cities, and other Italic peoples such as the Sabines, Etruscans and Samnites. By the late third century BC, Rome was undisputed ruler of the Italian peninsula, and became increasingly involved in foreign wars. In 146 BC the destruction of Carthage in the west and Corinth in the east left Rome as the undisputed ruler of the Mediterranean, from Spain to Syria. War and the resultant flood of spoils, people and ideas which poured back to Italy caused profound changes in Roman society, which the old political system could not assimilate. Bitter power struggles caused the Republic to fall apart in a series of bloody civil wars, and in an attempt to provide stability Julius Caesar became 'perpetual dictator' of the Roman state. It was his assassination in 44 BC, ironically by senators who wanted to keep the old regime, which really ended any possibility of the Republic continuing in its old form.