Greek influence was strong, and under the Romans, who called it Barium, it became an important port, the harbour being mentioned as early as 180 BC. Fishing was also significant in Roman times. A Saracen stronghold in the 9th century AD, the city became the seat of the Byzantine governor of Apulia in 885. It was captured for the Normans by Robert Guiscard in 1071. Peter the Hermit preached the First Crusade there in 1096, and a large party of crusaders embarked from its port. Razed by William the Bad of Sicily in 1156, Bari acquired new greatness under Emperor Frederick II (reigned 1220–50). An independent duchy under a succession of rulers from the 14th century, it passed from the Sforza family to the kingdom of Naples in 1558 and became part of the Italian kingdom in 1860.
Modern Bari consists of the old city on the peninsula dividing the old from the new harbours; the new city along the coast on either side; and the industrial area inland. The chief features of historic interest are in the old city, notably the 12th-century Romanesque cathedral; the Norman castle, rebuilt by Frederick II and later extended; and the Basilica of San Nicola, founded in 1087 to house the relics of St. Nicholas, the patron saint of Bari. The seat of an archbishop and of a university (founded 1924), the city has a provincial picture gallery and archaeological museum. The annual Fiera del Levante, an Occidental-Oriental trade fair, has been held since 1930.
On the east coast railway from Milan and Bologna to Brindisi, Bari has international air services from nearby Palese airport and steamer services to Adriatic ports, the Black Sea, and the Mediterranean. Bari is connected by motorway to other Adriatic cities and to Naples on Italy’s western coast. The city is an agricultural centre; its industries include food processing, petroleum refining, textile milling, printing, and the production of tobacco, sulfide, building materials, machinery, aluminum, and ironwork. A busy centre for sea trade with the Balkans and the Middle East, the Porto Nuovo exports wine, olive oil, and almonds. Pop. (2006 est.) mun., 326,915.