Collegiata di Santa Maria Assunta - Duomo di San Gimignano

The Collegiate Church stands on the west side of Piazza del Duomo, so named although the church has never been the seat of a bishop.[7] The church has an east-facing facade, and chancel to the west, as at St Peter's Basilica. The architecture is 12th and 13th century Romanesque with the exception of the two chapels in the Renaissance style. The facade, which has little ornament, is approached from the square by a wide staircase and has a door into each of the side aisles, but no central portal. The doorways are surmounted by stone lintels with recessed arches above them, unusual in incorporating the stone Gabbro.[8] There is a central ocular window at the end of the nave and a smaller one giving light to each aisle. The facade, which is stone, was raised higher in brick in 1340, when the ribbed vaulting was constructed, and the two smaller ocular windows set in.[7] Matteo di Brunisend is generally credited as the main architect of the medieval period, with his date of activity given as 1239, but in fact his contribution may have been little more than the design of the central ocular window.[8] Beneath this window is a slot which marks the place of a window which lit the chancel of the earlier church, and may be the most visible sign of the church's reorientation in the 12th century rebuilding, although this is not entirely agreed upon by scholars.[8]