These ones included seafarers like the Saxons and the Jutes, who were both Germanic tribes. The kingdoms in the north of present-day England, known as Hen Ogledd, were Sub-Roman Bryothonic tribes, and experienced Anglo invasions during the 500's too. Eventually, they were conquered by the Angles.
Because of the distinct lack of physical evidence or formal reports from this time, the theories around the Anglo-Saxon invasion and occupation of England differ somewhat. The next known piece of factual evidence (following the invasions) is that, by the seventh century, there were seven smaller Anglo-Saxon kingdoms. These were known as the Heptarchy and included Northumbria, Mercia, East Anglia, Essex, Kent, Sussex, and Wessex. One of the symptoms of the Heptarchy was the relative loss of Christianity.
Northumbria and Mercia started off as being the most influential and dominant of the sub-kingdoms. However, once the Vikings had invaded, Wessex came to be under the rulership of Alfred the Great and rose in its power and authority. Alfred the Great's grandson was Athelstan, who was responsible for uniting the smaller kingdoms of England into one major force in 927. When Edred conquered Eric Bloodaxe (a formidable Viking), this unification was further entrenched.
King Cnut the Great was the Viking king of Denmark, Norway, England and some areas in Sweden. He reigned from 1018 to 1035 and was a major figure in Medieval Europe. For a short time, he assimilated England into the major empire that had Denmark and Norway under it. However, when Edward the Confessor ruled (between 1042 and 1066), he restored the rule of the House of Wessex.