Among the buildings of Justinian I that were erected after the devastating fire in Byzantium in 532, the historian Prokopios describes also the monumental porch at the entrance to the courtyard of the new Senat House. It must have been very similar to the porch leading into the courtyard of the old Hagia Sophia that was destroyed in 532. Since this can be reconstructed by the remains found at the 1935 excavation in front of Hagia Sophia, we have used it here to visualise the description of Prokopios.