War between King Mithridates IV of Pontus and the Roman Republic
The Third Mithridatic War, the last and longest of the three Mithridatic Wars, was fought between Mithridates VI of Pontus and the Roman Republic. Both sides were joined by a great number of allies dragging the entire east of the Mediterranean and large parts of Asia into the war. The conflict ended in defeat for Mithridates, ending the Pontic Kingdom, ending the Seleucid Empire, and also resulting in the Kingdom of Armenia becoming an allied client state of Rome.
Third Mithridatic War on wikipedia