 Aristarchus is principally known from the works of the 1st-century historian Appian as well as the coinage issued in his name.Aristarchus was appointed, in 63 BC, by Pompey on his conquest of Colchis, a region on the Black Sea, in the course of the Third Mithridatic War which pitted Rome against Mithridates VI of Pontus.Aristarchus's becoming "a dynast of the Colchians" is reported by Appian.