4 – Anglo-Saxon and Viking Invaders 400 AD to 900 AD

 
Even before the Romans left, Anglo-Saxons were raiding the south east coast of Britain, and once the Roman Army left, they were more or less free to invade, pushing north beyond the present Scottish border. They ruled over what eventually became England for some 500 years.

The kingdom of Northumbria c 700 AD

The Anglo-Saxon kingdom of Northumbria was originally two kingdoms divided approximately around the River Tees: Bernicia was to the north of the river and Deira to the south. It is possible that both regions originated as native Celtic British kingdoms which the Germanic settlers later conquered,

Around 800 AD a new wave of Viking invaders arrived. They raided the east coast of England, and swept round the north of Scotland, occupying Orkney, Shetland and the Western Isles.