Romans lived collapsed. Since 509 B.C., Rome had been famous for its system of cooperative and participatory government that combined executive magistrates with an aristocratic Senate and democratic assemblies. For centuries, the republic persisted, and no single man ever seized power. But within 100 years of Rome’s imperial victories in 146, the republican system would be dead. The triumph of the Roman Republic was simultaneously the beginning of the end of the Roman Republic.
The Washington Post. October 11 2005
this, in a nutshell, it all began when the Romans overthrew their Etruscan conquerors in 509 B.C.E. Centered north of Rome, the Etruscans had ruled over the Romans for hundreds of years.
Once free, the Romans established a republic, a government in which citizens elected representatives to rule on their behalf. A republic is quite different from a democracy, in which every citizen is expected to play an active role in governing the state.