Lancashire (lăngˈkəshĭr, –shər) [key], county (1991 pop. 1,365,100), 1,878 sq mi (4,864 sq km), N England, on the Irish Sea. The historical county town is Lancaster, but the county's administrative offices are now in Preston. Administratively, the county is divided into the districts of West Lancashire, Chorley, South Ribble, Fylde, Preston, Wyre, Lancaster, Ribble Valley, Pendle, Burnley, Hyndburn, and Rossendale. Manchester and Liverpool, now administratively separate, were formerly the county's main cities.
Much of the county is lowland (the Lancashire plain) with occasional moors. The principal rivers are the Lune, the Wyre, and the Ribble. The coastline is low and broken by estuaries. Vegetables and dairy products are economically important, and market gardening is a major source of income near the Ribble estuary. Lancaster and Preston are industrial hubs. Lancashire in Anglo-Saxon times was part of the kingdom of Northumbria. In 1351 it was made a county palatine, and in 1399 the palatine rights were vested in the king. Lancashire's economic growth began in medieval times with the introduction of the woolen industry. The process was accelerated by the Industrial Revolution, and the population increased rapidly in the 19th and early 20th cent. In 1974, Lancashire was reorganized as a nonmetropolitan county.