St Mark's (Bascilica di San Marco) was founded in 823. It is built on a Greek-cross plan, surmounted by five domes, derived from the great Byzantine churches of Constantinople and particularly from the destroyed sixth-century church of the Holy Apostles built by Justinian. Seriously damaged by fire in 976, it was restored but was demolished for the erection of the building in its existing form between 1063 and 1094 by an unknown Greek architect. The new building was brick vaulted, making possible the interior mosaic decoration. Decoration of the interior and exterior was carried out in bursts until the sixteenth century, most notably in the thirteenth century, using splendid mosaic, marbles and carvings. It incorporates outstanding art treasures including much that was looted from Constantinople. These include the quadriga of four bronze horses (now replaced by copies) set above the central door. The early Byzantine decoration gives way firstly to Veneto-Byzantine and then predominantly Venetian forms, the last named having Byzantine, Oriental, Romanesque and finally Gothic references. Both in the carvings of the west front and in the building's interior mosaic decoration there is clear icongraphic intent. The building was the Doge's Chapel throughout the history of the Republic and used for State ceremonies, replacing San Pietro in the sesteire of Castello as Venice 's cathedral only in 1807. See Ruskin and St Mark's.