High Quality Content by WIKIPEDIA articles! The Roman Republic was the period of the ancient Roman civilization where the government operated as a republic. It began with the overthrow of the Roman monarchy, traditionally dated around 508 BC, and its replacement by a government headed by two consuls, elected annually by the citizens and advised by a senate. A complex constitution gradually developed, centered on the principles of a separation of powers and checks and balances. Except in times of dire national emergency, public offices were limited to one year, so in theory at least, no single individual could dominate his fellow-citizens.