In the Middle Ages, Ampezzo fell under the jurisdiction of the Patriarchate of Aquileia and of the Holy Roman Empire. In 1420, the village was conquered by the Republic of Venice. In 1508 it was conquered by the Habsburgs, and by 1511 people of Ampezzo swore loyalty to the Emperor Maximilian, and that area was subsequently adjoined to the region of Pusterthal. In 1797, when the Treaty of Campo Formio was signed, Napoleon initially permitted the Habsburg Empire to retain it, but in 1810 he added Ampezzo to the Department of Piave, following an attack on the town in which it was burned by the French. It was short-lived; the Austrian Empire reclaimed it in 1813, and it remained in its possession even after the battles of Custoza and Sadowa in 1866 when Venice was ceded to Italy. The town gained a reputation as a health resort; it was reportedly free of diseases such as cholera.