Bari (anc. Barium), a seaport and archiepiscopal sea of Apulia, Italy, capital of the province of Bari, situated on a small peninsula projecting into the Adriatic, 69 m. N.W. of Brindisi by rail. Pop. (1901) 77,478. The town consists of two parts, the closely built old town on the peninsula to the N., and the new town to the S., which is laid out on a rectangular plan. The former contains the cathedral of S. Sabino, begun in 1035 but not completed till 1171: the exterior preserves in the main the fine original architecture (notably the dome and campanile), but the interior has been modernized. Not far off is the church of S. Nicola, founded in 1087 to receive the relics of this saint, which were brought from Myra in Lycia, and now lie beneath the altar in the crypt. The facade is fine, and the interior, divided into three naves by columns, with galleries over the aisles, has fortunately not been restored; the vaulting of the crypt has, however, been covered with modern stucco. The church is one of the four Palatine churches of Apulia (the others being the cathedrals of Acquaviva and Altamura, and the church of Monte S. Angelo sul Gargano). Adjacent is the small church of S. Gregorio, belonging also to the 11th century.
The castle, built in 1169, and strengthened in 1233, lies on the W. side of the old town: it is now used as a prison. The old harbour lies on the E. side of the peninsula, and the new on the W. In the new town is the Ateneo, containing the provincial museum, with a large collection of vases found in the district, in which the pre-Hellenic specimens are especially important (M. Mayer in Römische Mitteilungen, 1897, 201; 1899, 13; 1904, 188, 276). Bari is the seat of the command of the IX. army corps, and the most important commercial town in Apulia. It manufactures olive oil, soap, carbon sulphide and playing-cards, and has a large iron foundry.
Barium does not seem to have been a place of great importance in early antiquity; only bronze coins struck by it have been found. In Roman times it was the point of junction between the coast road and the Via Traiana; there was also a branch road to Tarentum from Barium. Its harbour, mentioned as early as 181 B.C., was probably the principal one of the district in ancient times, as at present, and was the centre of a fishery. But its greatest importance dates from the time when it became, in 852, a seat of the Saracen power, and in 885, the residence of the Byzantine governor. In 1071 it was captured by Robert Guiscard. In 1095 Peter the Hermit preached the first crusade there. In 1156 it was razed to the ground, and has several times suffered destruction. In the 14th century it became an independent duchy, and in 1558 was left by Bona Sforza to Philip II. of Spain and Naples.