BURGHAL HIDAGE is a record made under Edward the Elder (899-925) of the arrangements made for maintaining the defensive system in Wessex, Sussex and Surrey, probably designed by his father Alfred in c.890. Every town and village was within 20 miles of a fortress, which was to be prepared and garrisoned by the men of the surrounding area. In wartime every perch of wall needed four men, each of whom was supported by one hide of land in a 20 mile radius. See BURH; BURH BOT.