A city of northeast Italy on islets within a lagoon in the Gulf of Venice, an inlet of the Adriatic Sea. Founded in the 6th century ad by refugees fleeing the Lombard invaders who had gained control of the mainland, it became a major maritime power by the 13th century and spread its influence over northern Italy and the eastern Mediterranean by the 15th century. Its territories were gradually lost to the Turks, and in 1797 it passed to Austria. Venice was ceded to Italy in 1866. It is a tourist and commercial center known for its canals.