[3] During the early 12th century the importance of San Gimignano, and its principal church, grew steadily, owing to the town's location on the pilgrimage route to Rome, the Via Francigena.

[3] The present church on this site was consecrated on 21 November 1148 and dedicated to St. Geminianus (San Gimignano) in the presence of Pope Eugenius III and 14 prelates.

[3] The church possesses the relics of St. Geminianus, the beatified Bishop of Modena and patron saint of the town, whose feast day is celebrated on 31 January.

[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] To the north side of the church, in the corner of the transept and chancel, stands a severely plain campanile of square plan, with a single arched opening in each face.

To the south side of the church is the Loggia of the Baptistry, a 14th-century arcaded cloister with stout octagonal columns and a groin vault.

[9] Internally, the building is in the shape of a Latin Cross, with central nave and an aisle on either side, divided by arcades of seven semi-circular Romanesque arches resting on columns with simplified Corinthianesque capitals.

[10] The Romanesque architectural details of the church's interior are emphasised by the decorative use of colour, with the voussoirs of the nave arcades being of alternately black and white marble, creating stripes, as seen at Orvieto Cathedral.

The church is most famous for its largely intact scheme of fresco decoration, the greater part of which dates from the 14th century, and represents the work of painters of the Sienese school, influenced by the Byzantine traditions of Duccio and the Early Renaissance developments of Giotto.

The remaining paintings, with the exception of a repainted panel in the sixth bay, are the work of Bartolo di Fredi, and, according to an inscription, were completed around 1356.

[12] The name "Barna" in relation to paintings at the Collegiate Church of San Gimignano appears to have originated in Lorenzo Ghiberti's Commentaries.

[15] The lower register, showing the Passion of Christ, continues beneath the Entry into Jerusalem, and is read from right to left in eight scenes over four bays.

[16] This chapel off the right aisle, which has been described as "one of the jewels of Renaissance architecture, painting and sculpture", is dedicated to a young girl, Serafina, known as "Fina" and regarded locally as a saint.

[17] On the day of her death, 12 March 1253, the bells of San Gimignano rang spontaneously, and large pale mauve flowers grew around her palette.

The side lunettes have frescoes by Niccolo di Lapi representing the Birth of the Virgin and St Philip Neri celebration mass.

The work was commissioned by the people of San Gimignano as the result of a vow that they made to honour the saint, whose intervention was believed to have brought relief from an outbreak of plague in 1464.

The painting shows the figure of Christ and the Virgin Mary in Glory, while below, St Sebastian, standing on a Classical plinth and bristling with arrows, suffers martyrdom and is crowned by angels.

It is hexagonal, with a sculptured relief on the side, that to the front being the Baptism of Christ, with the two adjoining panels containing kneeling angels.