The purpose of this article is to record the progress that has been made in certain projects of restoration and investigation in the Byzantine monuments of Istanbul. Attention was centered on three monuments: the north church, dedicated to Theotokos, of the monastery of Constantine Lips; the south church of the Pantocrator group (Zeyrek Camii); and the Parecclesion of the church of the Pammakaristos (Fethiye Camii). Comment is made on some of the more important objects that have been found in the course of the work on these three churches. During the period since the uncovering of the mosaic of the Emperor Alexander work on a smaller scale has been carried out in Hagia Sophia.