Gloucestershire (glŏsˈtərshĭrˌ, glôˈstər–) [key], county (1991 pop. 520,600), 1,025 sq mi (2,655 sq km), W central England. The county seat is Gloucester. Administratively, the county is divided into six districts: Forest of Dean, Stroud, Gloucester, Tewkesbury, Cheltenham, and Cotswold. South Gloucestershire is an administratively independent unitary authority. In the eastern part of the county are the Cotswold Hills, devoted largely to dairy and crop farming; in the center is the fertile valley of the Severn River, devoted to dairy farming (Gloucester cheese) and sheep raising; and in the west, on the Welsh border, are the Wye valley and the Forest of Dean, also with sheep raising. Manufacturing (aircraft, engineering, paper, and tobacco products) is centered in Gloucester and Cheltenham. Cirencester and Gloucester were centers of Roman road networks. The region became part of the Anglo-Saxon kingdom of Mercia. In the Middle Ages the Cotswolds provided wool for an important wool trade in the county.