Guthrum in the context of "Great Heathen Army"

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.

The Battle of Edington or Battle of Ethandun was fought in May 878 between the West Saxon army of King Alfred the Great and the Great Heathen Army led by the Danish warlord Guthrum. The battle took place near Edington in Wiltshire, where Alfred secured a decisive victory that halted the Viking advance into Wessex.

The engagement followed a period of sustained Danish incursions into Anglo-Saxon territory. In early 878, Guthrum launched a surprise attack on Chippenham, forcing Alfred into hiding in the marshes of Athelney. After rallying local forces, Alfred confronted and defeated Guthrum at Edington, then laid siege to the Viking position, compelling their surrender.

The Treaty of Alfred and Guthrum is a 9th-century peace agreement between Alfred of Wessex and Guthrum, the Viking ruler of East Anglia. It sets out the boundaries between Alfred and Guthrum's territories as well as agreements on peaceful trade, and the weregild value of its people.