The Senat House close to the Imperial Palace and to Hagia Sophia was first built after 360 and reconstructed by Justinian I. It is most probably identical with the reception hall of the emperor that was in use at least until the 10th century and mostly simply called Magnaura, from the latin Magna Aula (Great Hall). The description in the Book of Ceremonies of a reception for an Arabian embassy, that was held there in 946, suggests that the Magnaura was not basilical in shape, as this has usually been assumed, but rather a cross-in-square building with a dome, possibly as the result of Justinian's reconstruction.