Vikings in England

The kingdom of the East Anglia bordered the North Sea to the north and the east, with the River Stour dividing it from the East Saxons to the south. The North Sea provided a busy maritime link to Scandinavia and Northern Germany. The kingdom's western boundary varied from the rivers Ouse, Lark and Kennett to further westwards, as far as the Cam in what is now Cambridgeshire. At its greatest extent, the kingdom comprised the modern-day counties of Norfolk, Suffolk and parts of eastern Cambridgeshire. In 865, East Anglia was invaded by the Danish Great Heathen Army, which set up winter camp before departing for Northumbria. The Danes returned in 869 to winter at Thetford, before being attacked by the forces of Edmund of East Anglia, who was defeated and killed at Hægelisdun. From this point East Anglia effectively ceased to be an independent kingdom. Having defeated the East Anglia, the Danes installed puppet-kings to govern on their behalf, while they continued to campaign against Mercia and Wessex. In 878 the last active portion of the Great Heathen Army was defeated by Alfred the Great.

In 852 Burgred came to the throne, and with Ethelwulf of Wessex subjugated North Wales. In 868 Danish invaders occupied Nottingham. The Danes drove Burgred from his kingdom in 874 and Ceolwulf II took his place. In 877 the Danes seized the eastern part of Mercia, which became part of the Danelaw. Ceolwulf, the last king of Mercia, left with the western half, reigned until 879.From about 883 until his death in 911 Æthelred, Lord of the Mercians, ruled Mercia under the overlordship of Wessex. After Æthelred's death in 911, his wife Æthelflæd ruled as "Lady of the Mercians", but Alfred's successor as King of the Anglo-Saxons, Edward the Elder, took control of London and Oxford, which Alfred had placed under Æthelred's control.

The Viking invasions of the 9th century and the establishment of the Danelaw divided Northumbria. Although primarily recorded in the southern provinces of England, the Anglo-Saxon Chronicles (particularly the D and E recensions) provide some information on Northumbria's conflicts with Vikings in the late eighth and early ninth centuries. According to these chronicles, Viking raids began to affect Northumbria when a band attacked Lindisfarne in 793. After this initial blow, raids in Northumbria were either sporadic for much of the early 9th century or evidence was lost. However, in 865 the so-called Great Heathen Army landed in East Anglia and began a sustained campaign of conquest. The Great Army fought in Northumbria in 866–867, striking York twice in less than one year. After the initial attack the Norse left to go north, leaving Kings Ælle and Osberht to recapture the city. The E recension of the Anglo-Saxon Chronicle suggests that Northumbria was particularly vulnerable at this time because the Northumbrians were once again fighting among themselves, deposing Osberht in favor of Ælle. In the second raid the Vikings killed the Northumbrian kings Ælle and Osberht while recapturing the city.

In 802 the fortunes of Wessex were transformed by the accession to the throne of Egbert. In the beginning of his reign he conducted two campaigns against the "West Welsh", first in 813 and then 825. During the course of these campaigns he conquered the western Britons still in Devon and reduced those beyond the River Tamar, now Cornwall, to the status of a vassal. In 825-826 he overturned political order in England by defeating King Beornwulf of Mercia and as result seized control of Surrey, Sussex, Kent and Essex from the Mercians, and also assisted East Anglia to break away from Mercia’s control. Forty Years later, in 865, several of the Danish commanders combined their respective forces into one large army and landed in England. Over the following years, what became known as the Great Heathen Army overwhelmed the kingdoms of Northumbria and East Anglia. Then in 871, the Great Summer Army arrived from Scandinavia, to reinforce the Great Heathen Army. The reinforced army invaded Wessex and, although Æthelred and Alfred won some victories and succeeded in preventing the conquest of their kingdom, a number of defeats and heavy losses of men meant Alfred offered Danegeld to pay the Danes to leave Wessex. This held them off until 876, however their return was short lived and Alfred fought them off seeing the Vikings withdrawal from Wessex a year later. Some of the Vikings settled in Mercia, and early in 878 took Alfred by surprise with a winter invasion and overran much of Kingdom of Wessex. Alfred had to initially seek refuge in the marshlands of the Somerset levels, however after a few months he raised an army and defeated the Vikings, which brought about their final withdrawal from Wessex.