He was made by his father ruler of Colchis on the Black Sea, but then removed and put to death on suspicion of disloyalty.
[1] After the war, Mithridates VI had to deal with disturbances among his remote subjects, including those in Colchis, a country on the eastern Black Sea coast.
[2] The Colchians, dissatisfied with the previous administration of their country, requested that the king send his eldest son and heir, Mithridates, as their ruler.
The appointment of Mithridates the Younger as ruler of Colchis probably was of the same nature as the simultaneous installment of another son, Machares, as viceroy of Bosporus.
[2] The younger Mithridates's reign in Colchis was received with such a demonstration of favor from his new subjects as to excite the jealousy of his father.