Kingdom of East Anglia in the context of "Wuffingas"

Æthelred I (alt. Aethelred, Ethelred; Old English: Æthel-ræd, lit. 'noble counsel'; 845/848 to 871) was King of Wessex from 865 until his death in 871. He was the fourth of five sons of King Æthelwulf of Wessex, four of whom in turn became king. Æthelred succeeded his elder brother Æthelberht and was followed by his youngest brother, Alfred the Great. Æthelred had two sons, Æthelhelm and Æthelwold, who were passed over for the kingship on their father's death because they were still infants. Alfred was succeeded by his son, Edward the Elder, and Æthelwold unsuccessfully disputed the throne with him.

Æthelred's accession coincided with the arrival of the Viking Great Heathen Army in England. Over the next five years the Vikings conquered Northumbria and East Anglia, and at the end of 870 they launched a full-scale attack on Wessex. In early January 871, Æthelred was defeated at the Battle of Reading. Four days later, he scored a victory in the Battle of Ashdown, but this was followed by two defeats at Basing and Meretun. He died shortly after Easter. Alfred was forced to pay off the Vikings, but he scored a decisive victory over them seven years later at the Battle of Edington.

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 Heptarchy was the division of Anglo-Saxon England between the sixth and eighth centuries into petty kingdoms, conventionally the seven kingdoms of East Anglia, Essex, Kent, Mercia, Northumbria, Sussex, and Wessex. The term originated with the twelfth-century historian Henry of Huntingdon and has been widely used ever since, but it has been questioned by historians as the number of kingdoms fluctuated, and there was never a time when the territory of the Anglo-Saxons was divided into seven kingdoms each ruled by one king. The period of petty kingdoms came to an end in the eighth century, when England was divided into the four dominant kingdoms of East Anglia, Mercia, Northumbria, and Wessex.

Edward the Elder (870s? – 17 July 924) was King of the Anglo-Saxons from 899 until his death in 924. He was the elder son of Alfred the Great and his wife Ealhswith. When Edward succeeded to the throne, he had to defeat a challenge from his cousin Æthelwold, who had a strong claim to the throne as the son of Alfred's elder brother and predecessor, Æthelred I.

Alfred had succeeded Æthelred as king of Wessex in 871, and almost faced defeat against the Danish Vikings until his decisive victory at the Battle of Edington in 878. After the battle, the Vikings still ruled Northumbria, East Anglia and eastern Mercia, leaving only Wessex and western Mercia under Anglo-Saxon control. In the early 880s Æthelred, Lord of the Mercians, the ruler of western Mercia, accepted Alfred's lordship and married his daughter Æthelflæd, and around 886 Alfred adopted the new title King of the Anglo-Saxons as the ruler of all Anglo-Saxons not subject to Danish rule. Edward inherited the new title when Alfred died in 899.

The Great Heathen Army, also known as the Viking Great Army, was a coalition of Scandinavian warriors who invaded England in AD 865. Since the late 8th century, the Vikings had been engaging in raids on centres of wealth, such as monasteries. The Great Heathen Army was much larger and aimed to conquer and occupy the four kingdoms of East Anglia, Northumbria, Mercia and Wessex.

The name Great Heathen Army is derived from the Anglo-Saxon Chronicle. The force was led by three of the five sons of the semi-legendary Ragnar Lodbrok, including Halfdan Ragnarsson, Ivar the Boneless and Ubba. The campaign of invasion and conquest against the Anglo-Saxon kingdoms lasted 14 years. Surviving sources give no firm indication of its numbers, but it was described as amongst the largest forces of its kind.

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.

Angeln (pronounced [ˈaŋl̩n] ; Danish: Angel) is a peninsula on the Baltic coast of Jutland, in the Bay of Kiel. It forms part of Southern Schleswig, the northernmost region of Germany. The peninsula is bounded on the north by the Flensburg Firth, which separates it from Sundeved and the island of Als in Denmark, and on the south by the Schlei, which separates it from Schwansen. The landscape is hilly, dotted with numerous lakes. The largest towns are Flensburg, Schleswig and Kappeln.

Angeln is notable for being the putative home of the Angles, a Germanic tribe that migrated to Great Britain during the Age of Migrations and founded the kingdoms of Mercia, Northumbria and East Anglia. The Angles would ultimately give their name to England.