The Great Roman Civil War (49–45 BC), also known as Caesar's Civil War, was one of the last politico-military conflicts in the Roman Republic before the establishment of the Roman Empire. It began as a series of political and military confrontations, between Julius Caesar (100–44 BC), his political supporters (broadly known as Populares), and his legions, against the Optimates (or Boni), the politically conservative and socially traditionalist faction of the Roman Senate, who were supported by Pompey (106–48 BC) and his legions.