COSMATI, the name of a Roman family, seven members of which, for f our generations, were skilful architects, sculptors, and workers in mosaic. The following are known from existing in scriptions:— Their principal works in Rome are : ambones of S. Maria in Ara Coeli (Lorenzo) ; door of S. Saba, 12o5, and door with mosaics of S. Tommaso in Formis (Jacopo) ; chapel of the Sancta Sanctorum, by the Lateran (Cosimo) ; pavement of S. Jacopo alla Lungara, and (probably) the magnificent episcopal throne and choir-screen in S. Lorenzo fuori le Mura, of 1254 (Jacopo the younger) ; baldacchino of the Lateran and of S. Maria in Cos medin, c. 1294 (Adeodato) ; tombs in S. Maria sopra Minerva (c. 1296), in S. Maria Maggiore, and in S. Balbina (Giovanni). The chief signed works by Jacopo the younger and his brother Luca are at Anagni and Subiaco. A large number of other works by members and pupils of the same family, but unsigned, exist in Rome. These are mainly altars and baldacchini, choir-screens, paschal candlesticks, ambones, tombs, and the like, all enriched with sculpture and glass mosaic of great brilliance and decorative effect.
Besides mosaic patterns and architectural decoration, they also produced mosaic pictures and sculpture of very high merit, especially the recumbent effigies, with angels standing at the head and foot, in the tombs of Ara Coeli, S. Maria Maggiore and else where. One of their finest works is in S. Cesareo; this is a marble altar richly decorated with mosaic in sculptured panels. The magnificent cloisters of S. Paolo fuori le Mura, built about 1285 by Giovanni, the youngest of the Cosmati, are one of the most beautiful works of this school, whose style is Gothic in its main lines. The equally magnificent cloisters of the Lateran, of about the same date, are very similar in design; both have slender marble columns, twisted or straight, richly inlaid with bands of glass mosaic in delicate and brilliant patterns. The shrine of the Confessor at Westminster is a work of this school, executed about 1268.
An excellent account of the Cosmati is given by Boito, Architettura del medio evo (188o), pp. 117-182.