The parish church of SS Gervasio e Protasio in Prosito was built in the 13th century and was, perhaps, a private church. The center Monte Parli was the Chapel of San Martino di Monte Paglio, which was built in 1215. It was originally the parish church of the hamlets and was known as SS Placido e Sigisberto. The main church in Lodrino was the church of St. Ambrogio which was first mentioned in 1375. It was built on the foundation of a romanesque church from the 11th-12th centuries. The churches were supported in the Middle Ages by the Vicar of Biasca. When the Duke of Milan ceded the Levantine to Uri in 1441, he reorganized his holdings in the Riviera. The villages Lodrino, Prosito and Iragna were incorporated in a ducal vicariate, which was allowed to elect their own village officials. In the administration as well as civil and criminal law the villages were given considerable autonomy. They were given village statutes of 1450 and again in 1492. In 1496 Lodrino, Prosito and Iragna swore their loyalty to the Swiss Confederation.