In the course of the excavations carried on by the School from 1906 to 1910 at Sparta, a considerable quantity was found of the mediæval glazed pottery that is usually called Byzantine. As specimens of this fabric are not common in museums, and its date and general relations are still matters of some doubt, it seems desirable to publish all the pieces of any interest as material for further study, although the writers of this paper have no claim to speak as experts on the subject. The fragments were found in the numerous trial pits that were made on and around the Acropolis, and were especially abundant outside the east end of the Late Roman fortifications. The exactly similar ware from Pergamon and Constantinople now in the Kaiser Friedrich Museum at Berlin is there officially ascribed to the thirteenth and fourteenth centuries, and other pieces from old Cairo in the same museum of very similar make, to the eleventh and twelfth. Two almost complete bowls from Pergamon, on the other hand, plainly of our classes I and III, are assigned by W. Altmann to ‘the first centuries of Byzantine art’ The position in which the sherds were found at Sparta gives some slight indication as to date in the form of a probable terminus ante quem, for the building of the fortress of Misithra, or Mistrá, by Guillaume de Villehardouin, in the middle of the thirteenth century, was quickly followed by the decay of the Byzantine city situated round the Acropolis of Sparta.