The Church was firstly mentioned in written texts in 1247, as the municipality undertook to build the new parish church for the Civitate Nova (New Town). The need for a new church was due to the growth of the population: the existing Church of S. Bartolomeo, traditionally called Ecclesia de Castello, could not accommodate all the citizens and did not have enough burial ground. In 1249 the Church, which was still under construction, was ceded to the Hermits to promote the settlement of the monks in the city. After the construction of the Church of Sant’Agostino, the building was transformed into a convent. Subsequently the cloister was built in the area between the two churches, replacing the ancient graveyard. The complex of San Pietro all’Orto now hosts the Museum of Religous Art, the Collection of Contemporary Art “Angiolino Martini” and the Museum of the Ancient Mechanical Organs.