West Sussex, county (1991 pop. 692,800), 768 sq mi (1,990 sq km), S England. Chichester is the county seat. Administratively, the county is divided into the districts of Chichester, Arun, Worthing, Adur, Horsham, Crawley, and Mid Sussex. A chalk ridge runs from the county's east to west edge. In the south the land flattens into a gentle plain. After early Roman invasions, the Saxons moved across Sussex. The Normans deposed them, leaving behind monasteries and castles. West Sussex is essentially a resort area; Littlehampton, Bognor Regis, and Worthing are the most popular tourist spots. See also Sussex.