Durham, officially County Durham, county (1991 pop. 589,941), 1,015 sq mi (2,629 sq km), NE England, on the North Sea between the Tees and Tyne rivers; administratively, Durham is a unitary authority (since 2009). The administrative center is Durham, site of one of England's finest Norman cathedrals. The region is low-lying along the coast, rising inland to the Pennines. A large portion of the land area is devoted to agriculture. Dairy farming is common; cattle and sheep are raised. Oats, wheat, barley, potatoes, and turnips are grown. Industry is concentrated along the Tyne and the Tees. Shipbuilding (also along the Wear River) and coal mining were historically important. Electrical goods, clothing, textiles, paint, organs, and plastics are the chief products of Durham's light industry. The area was occupied by the Romans and subsequently became part of the Anglo-Saxon kingdom of Northumbria. From pre-Norman times until 1836, the bishops of Durham intermittently exercised palatine powers over the county. The powers were most important during the Middle Ages.