The Cathedral of Grosseto, dedicated to San Lorenzo, was built on the ruins of the Church of Santa Maria after that on April 9th 1138 after Christ the Bishop Rolando, who was supporting Innocenzo II during the period of the "schism anacletiano", obtained from the Pope the authorization to transfer the headquarter of the "Rosellana ecclesia" to Grosseto.
During the arch of the 12
th century, the role of the Cathedral in the city was led by the parish of Santa Maria Assunta, located more or less in the apse part of the actual construction, started in 1294 after Christ, as it was shown by the slabs of the façade and of the inside of the church, dating back to 1294 and for the second one to 1295 after Christ.
After the interventions launched in 1338 after Christ, at the time of the domination of Siena, in 1402 after Christ was built the belfry tower, restored and modified in 1911.
The façade has lost its original aspect, being completely rebuilt between 1816 and 1855 but, as a testimonial of the original aspect of the cathedral, are preserved fragments of the past eras, such as, for example, the symbols of the Evangelists.
Between 1859 and 1865 another big intervention of restoration gave to the inside of the cathedral a "gothic" aspect up to then unknown, that at the same time led to the disappear of the original decorations, work of the Siena born Sozzo da Rustichino.
To be admired, among other, a "Baptism Font" and "the altar of the Madonna of the Graces", both work of Antonio di Paolo Ghini realised between 1470 and 1474 after Christ, the marvellous Madonna of the Graces of Matteo di Giovanni, also from 1470 after Christ and the right side of the cathedral which, with its door embedded by briquettes with low relief and by geminate windows and tabernacles located on pillars, clearly declared references to the style of Siena.