The construction of the church started at the end of 1200 and was finally finished in the first decades of 1300. The monastery and the bishop’s seminary were built over the following centuries around the two large 16th-century cloisters.
The appearance of the church was undermined in its integrity and in its usability by the deterioration occurred over time, accentuated by the state of neglect in which the church poured.
The aim of the restoration was therefore to improve the legibility and
conservation conditions of the pictorial areas and the overall areas of the historical artefact.
After the building and the bell tower restoration, whose the most important works involved the removal of a reinforced concrete screed, placed on the top of the roof in the 90s, as it weighed down and bent the secondary roof frame, thus preventing rainwater from flowing regularly, proper measures were taken to set up a restoration workshop inside the church for the frescos, where visitors were able to observe the restoration techniques and the progress of the works.
The most well-known and important wall figures of the church are those created by renowned Master Bartolo di Fredi from Siena, who worked for Montalcino for a long time during the 1380s.
In addition to some figures representing female saints on the right-hand wall, Bartolo was assigned to the task of completely decorating the large chapel behind the major altar with paintings representing the stories of Saint Augustine and the two Apostles James and Philip.
The oldest painting, which represents Saint Augustine in the center and some scenes from his life, is located in a large square on the left-hand wall. This painting is a valuable and rare testimony of the author’s skills, who adopted Duccio di Buoninsegna’s style.