Udine (ōˈdēnā) [key], city (1991 pop. 99,189), capital of Udine prov., Friuli–Venezia Giulia, NE Italy. Manufactures include machinery, textiles, metals, and chemicals. In the 10th cent. Emperor Otto II gave the city to the patriarchs of Aquileia, who made it their capital (13th cent.). Udine has been the chief city of Friuli since the 15th cent. It passed to Venice in 1420 and to Austria in 1797 and 1814, and it was annexed by Italy in 1866. In World War I the city was the headquarters of the Italian army (1915–17) and was occupied by Austria (1917–18). In the Piazza della Liberta, the main square, are the Loggia di San Giovanni (16th cent.), with a clock tower; the Gothic town hall (1457); and a fine fountain (16th cent.). Overlooking Udine is a castle (early 16th cent.), which was the seat of the Venetian governors and now houses a museum of painting and numismatics. Nearby is Campo Formio, where a treaty between France and Austria was signed (1797).