What happened in the roman republic?

The Roman Republic existed for over 4 centuries. It was the phase of the ancient Roman civilization characterized by a republican form of government. It began with the overthrow of the Roman monarchy, c. 509 BC, and lasted over 450 years until its subversion, through a series of civil wars, into the Principate form of government and the Imperial period.

Because it existed for so long ... you're going to have to be a little more specific that "what happened?"