The beginning of Wessex may be traced to the baptism by St Birinus of King Cunegils and the creation of the diocese of Dorchester. This diocese was superceded by those of Winchester and Sherborne. The core of the kingdom lay in Hampshire, Wiltshire, Berkshire, Dorset and Somerset. The kingdom expanded with control over Devon and Cornwall, and later, in 825, over Surrey, Sussex, Kent and Essex. The story of the battles with the Danes is a complex one; the king to arise from it was Alfred and his son Edward the Elder. The Danes were banished from Mercia and East Anglia. King Athelstan recovered Northumbria which gave Wessex control of the whole country. The Kingdom of Wessex gave way to that of England.