Forum of Theodosius or Forum Tauri: second great market place in Constantinople.
The Forum Tauri, the "Market of the Bull" in Constantinople was created by Constantine the Great. It was situated along the main road of the new city, the Mese, ¾ km west of the Forum of Constantine, and is more or less identical to modern Beyazıt Square.
More than half a century after Constantine had created it - in 393, to be precise - the marketplace was redecorated by the emperor Theodosius I; it was from now on called Forum of Theodosius. It was Constantinople's largest public square. In the center, there appears to have been a large memorial column. A fragment of it survives and suggests that it had, like the Column of Trajan and the Column of Marcus Aurelius in Rome, a spiral-shaped decoration that showed soldiers in action.
When Beyazıt Square was rearranged in the 1950s, many fragments of the ancient market place were excavated. (Several large remains are now visible at the beginning of Ordu Caddesi.) It appears that the Forum of Theodosius was surrounded on all sides by marble porticoes, and it looks as if the public and civil buildings were also decorated with marble façades. During the excavations, some remains were found that belonged to the age before Constantine the Great, like the tombstone of Aurelius Surus, who had been trumpeter of the First legion Adiutrix.
In the southwest corner of this square market was an enormous triumphal arch. The Arch of Theodosius had three passageways, the central one being, as was usual, higher than the others. In the middle may have been a statue of the emperor himself, with statues of his sons Arcadius and Honorius standing on top of the smaller arches.
Over the ages, Constantinople has suffered from several natural disasters. It was also sacked by the Crusaders in 1204. The Forum of Theodosius was probably destroyed and abandoned well before the city itself was in 1453 captured by the Ottomans.