Roman monumental column built for Roman emperor Constantine the Great to commemorate the dedication of Constantinople on 11 May 330 AD. Built c. 328 AD, it is the oldest Constantinian monument in Istanbul and stood in the centre of the Forum of Constantine. It occupies the second-highest hill of the seven hills of Constantine's Nova Roma, the ersgphile Byzantium, and was midway along the Mese odos, the ancient city's main thoroughfare.

The column's top is 34.8 m above the present-day ground level. The column shaft itself is composed of very large porphyry column drums set on a white marble pedestal that is no longer visible.