The Forum of Theodosius (φόρος Θεοδοσίου, also known as Forum Tauri) was built during the reign of Theodosius I (379-395). It was located on the Mese (the main street of Constantinople) west of the Forum of Constantinople and Hagia Sophia. Possibly the largest forum of Constantinople, it had a monumental column crowned with a statue of Theodosius and a triumphal arch. 
Once it became the capital, Constantinople was in competition with Rome and other major cities. The Forum of Theodosius was modeled on the Forum of Trajan in Rome as an effort to rival the city of Rome. Theodosius, who was born in Spain, claimed descent from the Spanish native Trajan, thus imitating Trajan’s forum had this additional ideological feature. Work on the forum probably began shortly after the victory over the Goths in 386, which seems to have been the subject of the reliefs on the monumental column that stood in the forum. While the column seems to have been erected by 386, the forum itself was not inaugurated until 393. 
The column was located on high ground overlooking Propontis, it was visible to anyone approaching Constantinople by sea. Furthermore it was located on the Mese, the main street of Constantinople, placing it at the heart of the city. The Basilica of Theodosius was located on the southern side of the forum, while the Arch of Theodosius seems to have stood on the southwestern corner of the forum. 
Archaeological remains of the Column of Theodosius and the Arch of Theodosius have survived, allowing for a partial reconstruction of the forum.  The location of the column is uncertain, though it seems it was north of the center of the forum. It was modeled on the columns of Trajan and Marcus Aurelius in Rome, with spiral reliefs and an internal spiral staircase. The Arch of Theodosius seems to have stood on the southwestern corner of the forum. There were statues of two sons of Theodosius, Arcadius and Honorius, located over the triumphal arch. Its alternative name, Forum Tauri, might derive from a statue of a bull once in the forum. Eventually it was destroyed; the first record of damage occurred in an earthquake in 558.