The First Mithridatic War (89–85 BC) was a war challenging Rome's expanding Empire and rule over the Greek world. In this conflict, the Kingdom of Pontus and many Greek cities rebelling against Rome were led by Mithridates VI of Pontus against the Roman Republic and the Kingdom of Bithynia. The war lasted five years and ended in a Roman victory which forced Mithridates to abandon all his conquests and return to Pontus. The conflict with Mithridates VI would continue in two further Mithridatic Wars.