Mithridates became king when he was only twelve, and so, it was his mother who actually wielded power. However, when he was seventeen, he had his mother imprisoned, and seized power. He also killed off several of his brothers to eliminate any competition for the throne!
Mithridates invaded Bithynia, which was a Roman ally, and this brought him into conflict with Rome. Later, Roman general Sulla captured Athens, and defeated Mithridates at the Battle of Chaeronea in 86 BC. Mithridates fought three wars against the Romans. Eventually, he lost his kingdom, and died after being overthrown by one of his sons.
Today, Mithridates VI is remembered as one of the Roman Republic’s most persistent enemies, though he won only one major battle.