The forum of Theodosios was built in the years after 380 and inaugurated in 393. The ruins of the Arch of Theodosios are the only part of it that can be reconstructed on the base of archeological evidence. Until recently, the Forum of Theodosios was believed to have been much bigger than it is shown here. The present reconstruction is based on the remains of the foundation walls found in the vicinity of the Arch. They prove that the forum actually was a square of about 55 x 55 m with an exedra to the north. The column of Theodosios which was very similar to the Column of Arkadios and is now lost stood on this square.