The foundation of the Cathedral of San Martino at Lucca is, according to tradition, attributable to Saint Frediano, the Bishop of Lucca who died in 588. Bishop Giovanni I decided, in 780, to bring the body of Saint Regolo here from Populonia, leading to the construction of a crypt and a new, sumptuous presbytery decorated in marbles and metallic gates. As early as 855 the facade boasted a porch which was destroyed in 905 and rebuilt in 928. Between 1060-1070 the church was completely rebuilt at the wish of Anselmo da Baggio, who became Pope Alessandro II (1061-1073) and who consecrated the church in the presence of 23 bishops and Matilde di Canossa.
In 1308 Bishop Enrico II gave 14 braccia at the east end of the church allowing them to construct the present day tribune and apse. During the 14th century it was decided to undertake a reconstruction of the entire church, work which intensified around 1374, executed by Florentine architects and finished in 1476. At that point the interior was re-embellished with works by Matteo and Vincenzo Civitali, Giambologna and Muzio Oddi. Of particular importance is the funerary monument to Ilaria del Carretto by Jacopo della Quercia (1408).