According to later tradition, the arrival of the West Saxons was dated around AD 495. Their kingdom, Wessex, as it became, covered the area of modern Hampshire. By 700 it had expanded into the areas of modern Dorset and Wiltshire. Under Ecgberht (839), modern Sussex, Surrey, Essex and Kent were annexed, and Wessex replaced Mercia as the dominant Anglo-Saxon kingdom.

Wessex prospered for much of the 9th century, while the rest of England was devastated by Viking raids. However, Wessex itself was attacked by the ‘Great Army’ of the Danes in 871 and despite trying to repel them, did not finally defeat them until 878. The victorious king of Wessex, Alfred (reigned 871-99), then brokered a treaty which ensured that Wessex would not be attacked again.

Wessex was now secure and Alfred built a series of fortified towns (burhs), organised an efficient militia and a navy. During the 10th century Anglo-Saxon kingdoms outside the Danelaw were gradually evolving into a single nation, but the kings of Wessex were still politically at the forefront. By the 11th century, Wessex was no longer a kingdom but an earldom of England. However, it remained powerful and in January 1066 the last English king to be crowned was Harold Godwinson, earl of Wessex.