Ancient Anglo-Saxon kingdom, southern England.
Its area approximated that of the counties of Hampshire , Dorset , Wiltshire , Somerset , Berkshire , and Avon . Its capital was Winchester . The kingdom is traditionally thought to have been founded by Saxon invaders of Britain с 494. Wessex conquered Kent and Sussex, and in the 9th century, under King Alfred the Great, it prevented the Danes from conquering England south of the Danelaw . By 927 Wessex had reconquered the Danelaw, and Alfred's grandson, Athelstan, had become king of all England; thereafter all kings of Wessex were kings of England. The region figures prominently in legends of King Arthur (see Arthurian legend ), and the designation "Wessex" was used by Thomas Hardy to represent the region of southwestern England in which he set his works of fiction.