The Byzantine Churches of Mystras
Seven Byzantine churches of Mystras, dating from the late 13th to the early 15th centuries, have been preserved. Their plans are varied and show an awareness of contemporary trends in Constantinople, though one particular plan survives nowhere else and may be a local invention. Their masonry, for the most part a sober cloisonné, exhibits in some cases lively patterns of a Constantinopolitan type. Much of the interior stone carving consists of spolia, mostly medieval, robbed probably from buildings in the city of Sparta. Frankish elements appear frequently in such architectural details as pointed windows but do not affect the actual church plans. Similarly, Western elements invade individual frescoes but never the overall program of decoration. The latter follows the general course of late Byzantine monumental painting, with a growing emphasis on liturgical themes and extended secondary cycles, especially those of Christ and the Virgin, at the expense of hagiographical cycles and the isolated portrait.
Oxford Byzantine Dictionary