The Column of Constantine was erected by him in 328 CE during the rebuilding and founding of his Imperial capital New Rome - Constantinople. It was placed in the Forum of Constantine, about a kilometre west of the Hagia Sophia. Fire (perhaps from the time of the Nika riots during the reign of Justinian in the 6th century), caused damage (as evidenced by its blackened appearance). Originally it was topped by an Apollo-like statue of the emperor - "Sol Invictus" - but the column was largely destroyed by a storm in the 12th century and as a protection against total loss to earthquakes iron hoops were later added. Still standing it is a sorry echo of a once-mighty and extravagantly colourful empire.
A sketch-map of ancient Constantinople can be found here
