According to tradition, the Dome of Lucca is dedicated to St. Martin and was founded by St. Frediano in the VI century. In the year 1060, it was rebuilt by the city's bishop, Anselmo da Baggio (the future Pope Alexander II), and it was later renovated between the XII ad the XIII centuries.

Guidetto da Como made its façade and it was inspired by the Pisa's Dome façade, even though it has its autonomous and original elements typical of the Romanesque style of Lucca.
On the ground floor there is a colonnade with three arcades that are supported by huge composite pillars; above, there are three orders of little lodges that recall the pattern of the Pisa's Dome façade. The three arcades are not of the same width because of the asymmetry of the façade, which narrows near the embattled bell tower, dating back to the XIII century, too.
Originally, there was a group of statues representing "St. Martin giving his mantle to the Poor" on the wall of a pendentive between two arcades of the colonnade (it is now kept inside the Dome and substituted by a copy on the outside). It dates back to 1233 almost and is one of the first medieval group of statues that are not submitted to an architectural function.
Furthermore, during the same years, various artists participated to the decoration of the portals of the façade: there is a relief portraying "The Ascension of Christ" in the lunette of the central portal and the "Stories of St. Martin" and the "Cycle of Months" are in the panels between the portals.
"The Martyrdom of St. Regulus" is in the lunette of the right lateral portal while the "Stories of Christ's Childhood" and the "Deposition" consist of reliefs on the left portal attributed to the Nicola Pisano's school.
The inside of St. Martin's Cathedral, renovated in the second half of the XIV century, has three naves with intervals of pilasters having projecting transepts and a semicircular apse.
Very precious works of art are preserved here, among which there is the burial monument of Ilaria del Carretto by Jacopo della Quercia (1408) that is kept in the sacristy where it is also possible to see a painting by Domenico Ghirlandaio showing "The Virgin Mary with the Holy Child among SS. Peter, Clement, Paul and Sebastian". On the altars of the right nave there is the "Adoration of the Magi" by Federico Zuccari and the "Last Supper" by Jacopo Tintoretto.
In the chapel of the sanctuary there is a painting portraying the "Virgin Mary and the Holy Child between the Saints" by Brother Bartolomeo (1509).
Moreover, at the centre of the left nave the so-called "Tempietto del Volto Santo" can be seen, too. This is a XV century structure that contains the famous "Volto Santo di Lucca" on the inside. This is a wooden crucifix created between the XI and the XIII centuries and it probably imitates a more ancient oriental model.
According to tradition, the "Volto Santo di Lucca" was carved by the Pharisee Nicodemus and it has been at the centre of a great worshipping, being a destination of pilgrimage from Italy and other European countries since the early Middle Ages.