 He played a leading role in resisting Mithridates VI of Pontus on Lesbos in the 80s BC.He met Pompey, the successful, young, Roman general who was nicknamed "the Great" ("magnus"), when the latter was using Mytilene as a naval base against pirates in 67BC, and became a member of his retinue.Theophanes was one of the most intimate friends of Pompey, whom he accompanied in many of his campaigns, and who frequently followed his advice on public as well as private matters.