Alfred the Great (Old English: Ælfrǣd [ˈæɫvˌræːd]; c. 849 – 26 October 899) was King of the West Saxons from 871 to 886, and King of the Anglo-Saxons from 886 until his death in 899. He was the youngest son of King Æthelwulf and Æthelwulf's first wife Osburh, who both died when Alfred was young. Three of Alfred's brothers, Æthelbald, Æthelberht and Æthelred, reigned in turn before him. Under Alfred's rule, considerable administrative and military reforms were introduced, prompting lasting change in England.
After ascending the throne, Alfred spent several years fighting Viking invasions. He won a decisive victory in the Battle of Edington in 878 and made an agreement with the Vikings, dividing England between Anglo-Saxon territory and the Viking-ruled Danelaw, which consisted of Scandinavian York, the north-east Midlands, and East Anglia. Alfred also oversaw the conversion of Viking leader Guthrum to Christianity. He defended his kingdom against the Viking attempt at conquest, becoming the dominant ruler in England. Alfred began styling himself as "King of the Anglo-Saxons" after reoccupying London from the Vikings. Details of his life are described in a work by 9th-century Welsh scholar and bishop Asser.