Mithridates or Mithradates VI Eupator (Ancient Greek: Μιθριδάτης;[2] 135–63 BC) was the ruler of the Kingdom of Pontus in northern Anatolia from 120 to 63 BC, and one of the Roman Republic's most formidable and determined opponents. He was an effective, ambitious, and ruthless ruler who sought to dominate Asia Minor and the Black Sea region, waging several hard-fought but ultimately unsuccessful wars (the Mithridatic Wars) to break Roman dominion over Asia and the Hellenic world.[3] He has been called the greatest ruler of the Kingdom of Pontus.[4] He cultivated an immunity to poisons by regularly ingesting sub-lethal doses; this practice, now called mithridatism, is named after him. After his death, he became known as Mithridates the Great.
Mithridates is the Greek attestation of the Iranic name Mihrdāt, meaning "given by Mithra", the name of the ancient Iranian sun god. The name itself is derived from Old Iranian Miθra-dāta-. The epithet "eupator" means "of a well (noble) father", and was adopted by a number of other Hellenistic rulers as well.[7]