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.
Guthrum (Old English: Guðrum, c. 835 – c. 890) was King of East Anglia in the late 9th century. Originally a native of Denmark, he was one of the leaders of the "Great Summer Army" that arrived in Reading during April 871 to join forces with the Great Heathen Army, whose intentions were to conquer the kingdoms of Anglo-Saxon England. The combined armies were successful in conquering the kingdoms of East Anglia, Northumbria, and parts of Mercia and overran Alfred the Great's Wessex but were ultimately defeated by Alfred at the Battle of Edington in 878. The Danes retreated to their stronghold, where Alfred laid siege and eventually Guthrum surrendered.
Under the terms of his surrender, Guthrum was obliged to be baptised as a Christian to endorse the agreement and then leave Wessex. The subsequent Treaty of Alfred and Guthrum set out the boundaries between Alfred and Guthrum's territories, as well as agreements on peaceful trade and the weregild value of its people. The treaty is seen as the foundation of the Danelaw. Guthrum ruled East Anglia under his baptismal name of Æthelstan until his death.
The Kingdom of the East Angles, informally known as the Kingdom of East Anglia, was a small independent kingdom of the Angles during the Anglo-Saxon period comprising what are now the English counties of Norfolk and Suffolk and perhaps the eastern part of the Fens; the area still known as East Anglia.
The kingdom formed in the 6th century in the wake of the Anglo-Saxon settlement of Britain and was one of the kingdoms of the Heptarchy. It was ruled by the Wuffingas dynasty in the 7th and 8th centuries, but the territory was taken by Offa of Mercia in 794. Mercian control lapsed briefly following the death of Offa but was reestablished. The Danish Great Heathen Army landed in East Anglia in 865; after taking York it returned to East Anglia, killing King Edmund ("the Martyr") and making it Danish land in 869. After Alfred the Great forced a treaty with the Danes, East Anglia was left as part of the Danelaw.