From Wikipedia

Monarchy

The Early Kings

The history of Anglo-Saxon England covers the history of England from the end of Roman Britain and the establishment of Anglo-Saxon kingdoms in the fifth century until the Norman Conquest of England in 1066. The fifth and sixth centuries are known archaeologically as Sub-Roman Britain, or in popular history as the 'Dark Ages'; from the sixth century larger distinctive kingdoms are developing, still known to some as the Heptarchy. For most of this period England was split between areas controlled by the Anglo-Saxons and by the British. The arrival of the Vikings at the end of the eighth century brought many changes to Britain. Danish raiders attacked places throughout Britain but their later settlement was restricted to the eastern part of England, while Norwegian raiders (via Ireland) attacked the west coast of both England and Wales. Eventually the Anglo-Saxons gained control of the whole of England though there was a short intermission of Danish control. Relations with the continent were important right up to the end of Anglo-Saxon England, traditionally held to be the Norman Conquest.

Alfred The Great
(Old English: Ælfrēd, Ælfrǣd, "elf advice"; 849 – 26 October 899), was king of the Anglo-Saxon kingdom of Wessex from 871 to 899. Alfred is noted for his defence of the Anglo-Saxon kingdoms of southern England against the Vikings, becoming the only English king to be given the epithet "the Great". Alfred was the first King of the West Saxons to style himself "King of the Anglo-Saxons". Details of his life are described in a work by the Welsh scholar and Bishop, Asser. Alfred was a learned man who encouraged education and improved his kingdom's legal system and military structure.

Britain about the year 802, showing the Anglo-Saxon kingdoms in red/orange and the Celtic kingdoms in green.