Kritoboulos states that Mehmed crossed the Taurus Mountains, becoming one of only four generals to have crossed them (the others being Alexander the Great, Pompey, and Timur).[27] However, as his translator Charles Riggs points out, to Kritoboulos all of the mountain systems of Asia Minor were part of the Taurus.[28] Doukas states that Mehmed led his soldiers across Armenia and the Phasis River, then ascended the Caucasus Mountains before reaching Trebizond.[29] This makes no sense when one examines a map, for both the Phasis River and the Caucasus are far to the east of their destination.