Which monumental column in Constantinople commemorated its founding by Constantine I?

The Column of Constantine commemorated the dedication and founding of Constantinople by Constantine the Great. The monumental porphyry column stood at the center of the Forum of Constantine, along the city’s main thoroughfare, the Mese.

Constantine established Constantinople as a new imperial capital on the site of Byzantium, and the city was formally dedicated on 11 May 330. The column originally stood about 50 meters high and was made from stacked cylindrical blocks of Egyptian porphyry, a rare purple stone associated with imperial power. A statue of Constantine, portrayed with solar imagery, once stood at its summit.

The monument suffered damage from fires, earthquakes, storms, and warfare. In 1106, a gale toppled the statue and several upper sections. A cross later replaced the statue, and Ottoman repairs added iron hoops around the shaft. These hoops gave the surviving monument its Turkish name, Çemberlitaş, meaning “hooped stone.” It still stands in Istanbul near the historic site of the forum.