Mosaic

   A technique invented by the ancients to decorate the interior surfaces of domestic and public spaces. It entails gluing the minute tesserae produced by cutting colored stones or glass onto wall, ceiling, or floor surfaces to create decorative patterns or fully developed scenes. In public spaces, such as the apses of pagan basilicas, mosaics served as a regal backdrop for the enthroned emperor. These scenes were usually mythological, though at times political images were also produced. With the introduction of Christianity as the Roman Empire's official religion, the need arose for decorations for newly built churches and other sacred structures. The sparkling effects created by the colored tesserae in the mosaics became symbolic of heaven—the reward granted to the faithful after death. Church apses became the main focus of mosaic decoration since it is here where the mass takes place and where the host is consecrated. Mosaics, however, also were used to cover the triumphal arch preceding the apse, and the solid walls above the nave arcade. The scenes depicted were usually religious narratives that instructed the faithful on Christian doctrine, including the story of salvation through Christ, the life of the Virgin Mary, or the cults of the saints. The use of mosaics as religious decorations continued well into the 13th century. Jacopo Torriti was responsible for the mosaics in the Basilica of St. John Lateran (c. 1291) and Santa Maria Maggiore (c. 1294), both in Rome. Coppo di Marcovaldo is credited with the mosaics of the Last Judgment on the vault of the Baptistery of Florence, and Giotto is known to have created a large mosaic for the courtyard façade of Old St. Peter's in c. 1307 depicting the scene where Christ walks on water to save St. Peter from drowning, the Navicella (destroyed in the 16th century).

   See also Cosmatesque style.