Inhabited since the 2nd century BC by the Carnic communities, Prato Carnico was later reached by the Romans and then by the Lombards. It is certain that the patriarchal authority was present in the Castle of Pradumbli (derived from “Pratus Domini,” meaning lord’s meadow, i.e., the patriarch) before 1225. The French invasion of 1797 ended these arrangements. With the Treaty of Campoformido, Prato Carnico became part of the Austrian Empire, but was joined to the Kingdom of Italy in 1805. After the Restoration, the entire valley returned under Austria until 1866, when it was annexed to Italy. Numerous churches, rich in art, are present in the municipality, including the parish church of San Canciano (dating back to the 14th century), the 18th-century parish church of Sant’Antonio in Pieria, and the church of San Leonardo in Osais (dating back to 1391).
