Mithridates VI of Pontus

After his father Mithridates V was assassinated, the teenage king ascended under his mother's regency until he overthrew her in 113 BC. He built Pontus into a regional power by subjugating Colchis and the Cimmerian Bosporus, but his westward push brought collision with Rome. In 89 BC he crushed Bithynia's invasion, swept into Roman Asia during the Social War, and rallied much of Greece - including Athens - to his banner as a champion of Hellenism. Sulla beat him back in the First Mithridatic War but cut a lenient peace to settle Rome's civil strife. A second war in 83 BC ended in another stalemate. The third began in 73 BC when he invaded Bithynia; Lucullus routed him, forcing him to flee to Armenia, though he briefly retook Pontus with a victory at Zela in 67 BC. Pompey crushed him at the Lycus a year later. Cornered in Crimea, facing rebellion from his own son, he killed himself at Panticapaeum in 63 BC.