Wikipedia has: Most likely, the column was erected to honor the victories of either Claudius II Gothicus (r. 268-270) or Constantine the Great (r. 306-337), both of whom are noted for achieving victories over the Goths. According to Byzantine historian Nicephorus Gregoras (c. 1295-1360), the column was once surmounted by a statue to Byzas the Megarian, the semi-legendary founder of Byzantium. A notice on location states “6th century historian Ionnes of Lydia mentions that the column head carried the sculpture of Tyche …” and suggests ".. a pagan goddess, it might have been removed following the approval of Christianity as the official religion.” It then quotes the (much later) Nikephoros Gregoras and the Byzas statue.

At any rate, it represents the oldest monument of the Roman era still extant in the city,[2] possibly going back to the city's history as Byzantium and preceding its refoundation as Constantinople.