Bisceglie (bēshĕl`yēā), city (1991 pop. 47,408), Apulia, S Italy, on the Adriatic Sea. It is a seaport, resort, and commercial center. Conquered by the Normans in the late 11th cent., the city later developed a prosperous merchant and military fleet. The duchy of Bisceglie was (16th cent.) a fief of Alfonso of Aragon, 2d husband of Lucrezia Borgia, and of their son Rodrigo. There are several churches of the 11th–12th cent., a fine Apulian Romanesque cathedral (11th–13th cent.), and ruins of an 11th-century Norman castle.