The building of Basilica di San Marco was started at the beginning of the 9th Century following the need for a place to house the relics of St Mark the Evangelist of Alexandria. The first location was constructed in 828 and represented nothing more than a temporary chapel on the premises of the Doge's Palace. The temple was destroyed and rebuilt two times before the contemporary cross-formed Byzantine basilica with five enormous domes appeared during the 11th Century.

The church was consecrated in 1094. After this date Basilica di San Marco was gradually expanded and many new features, such as the modern facade and the narthex, were added. Adjoined to the main structure are also the famous Campanile and the low tower that currently houses St Mark's treasure. However, decoration projects lasted much longer, with some of the carvings and ornaments being added until the Renaissance epoch. The most spectacular pieces of art that form the unique architecture of the huge building are the bronze replicas of the Greek Horses, whose originals were brought from Constantinople, and after a short period in Paris during the reign of Napoleon they were sent back to Venice and are now kept in the Museum of St Mark.

The basilica is also particularly famous for its mosaics, which decorate some of the spaces inside the temple like the Baptistery, the Mascoli Chapel, the St Isidor Chapel and the Zen Chapel. They were created by the great artists and painters Paolo Uccello, Jacopo and Domenico Tintoretto, Tiziano and Andrea del Castagno. The Pala d'Oro is also worth seeing, being noted as the most beautiful and most valuable altar screen worldwide with more than 3,000 pieces of precious stone and gold. Since 1807 Basilica di San Marco has been the seat of the Patriarch of Venice.