DURING THE early Middle Ages a large number of pagan buildings in Rome were adapted for Christian use. Outstanding among these is the group converted into diaconiae -Christian institutions devoted primarily to public welfare. There were twenty-two diaconiae existing in 800 A.D.; of these six have vanished so completely that we do not even know their precise locations. But utilization of ancient buildings by the rest is indicated either by traces of ancient walls or by strong traditions for ancient buildings on their sites and in nine of them the actual pagan fabric may still be seen. There is no indication in any of the available sources that the Church was hesitant about using these pagan structures or that the State was reluctant to have her do so. In fact, preservation of temples and other public buildings as monuments to the past glories of Rome was fostered by a strong feeling of civic consciousness which lasted well into the Middle Ages. But such maintenance of buildings was a troublesome and expensive matter and one gathers the general impression that the government was only too happy to pass on this problem to the Church along with the greater responsibility of caring for the populace. All the known buildings taken over by the Christians for diaconiae were monumental in character; in no case is there proof for use of domestic or private structures.1 There is ample evidence, too, for relating them to various aspects of the Roman system of public charity. Porticoes, shops, and markets served as distribution centers, granaries for storage and distribution, and certain other buildings for administration of all this decidedly large-scale activity. In general, Christianization of the buildings made little, if any, change in their appearance. Indeed, were it not for the small chapels created within them (often merely by addition of altars), or for the Christian themes of the paintings and mosaics placed on a few walls, one would scarcely be aware of any transformation. Among the buildings first taken over by the Church was a roofed loggia in the headquarters of the imperial administrator of public supplies of grain for the city.2 This loggia, built in the late fourth century, was part of a complex of porticoes, halls, and temple standing in the Forum Boarium, the region near the Tiber where centered the industrial and commercial activity of the city, conveniently near wharves and warehouses. The loggia, which had been used as a merchants' exchange, was rectangular in plan, roughly 50 feet wide by 100 feet long, and stood on a podium. Its back wall, which also served as a wall for the adjacent temple, was of brick; the other three sides were open arcades supported by columns, and the area was probably covered by a wooden roof. Within this in the early sixth century was erected the small chapel of the diaconia of S. Maria in Cosmedin. This was placed toward one end of the loggia, utilizing for its fagade the second and third columns of the row of seven across the front of the ancient exchange (Fig. 1). It was narrow: only 24 feet in width, with its main axis running through the depth of the loggia. The floor level of the chapel was apparently brought down to the level of the street-for greater ease of access-by cutting into the podium of the loggia; this gave the little chapel a height of about 34 feet. Most probably it was a very simple, single-naved structure with no apse. The remaining area of the loggia and the other buildings in the complex must have been used by the diaconia, but there is no remaining architectural evidence to indicate specific functions. Since the size and appearance of the chapel were so unimpressive, and its liturgical role apparently negligible, its importance lay chiefly in the fact that it served as a symbol of Church sponsorship of the administration of food supplies. The same statement applies to the instances where the Church took over State granaries. These were buildings of fireproof stone or brick, often of tremendous size, formed of numerous long low vaulted cells aligned in one or more stories around open courtyards. In the crypt of S. Maria in Via Lata one may trace the conversion of just one cell in a large granary into a Christian chapel.3 This was even smaller than that of S. Maria in Cosmedin, being only 11 by 18 feet in size, and even less conspicuous. Its Christian character was indicated merely by the addition FRANCES J. NIEDERER is on the faculty of fine arts of Hollins College.