Cnut the Great Conquers England (1016): A North Sea Empire

Cnut the Great conquered England in 1016 after a hard-fought war against the English prince Edmund Ironside, which ended with Cnut’s victory at the Battle of Assandun in Essex on 18 October. When Edmund died a few weeks later, the Danish prince became king of the whole country. Within a dozen years Cnut also ruled Denmark and Norway, creating a North Sea empire that made England the centre of a Scandinavian realm.

Background: England’s long Viking crisis

England under King Æthelred II had suffered renewed Viking attacks since the 980s. After the Battle of Maldon in 991, the English paid ever larger tributes to raiding armies, and the St Brice’s Day Massacre of 1002 showed how tense relations with the Danes had become.

In 1013 the Danish king Sweyn Forkbeard invaded with the aim of conquest, accompanied by his young son Cnut. The north and east submitted quickly, and by the end of the year Æthelred had fled to Normandy. Sweyn was accepted as king, but he died suddenly on 3 February 1014.

The Danish fleet chose Cnut as Sweyn’s successor, but the English magnates invited Æthelred back. Cnut, still in his late teens or early twenties, withdrew to Denmark. Before sailing he put ashore at Sandwich the English hostages his father had taken, after cutting off their hands and noses.

The invasion of 1015

Cnut returned in late summer 1015 with a large fleet. His brother Harald, now king of Denmark, supported the expedition, and he was joined by experienced commanders such as Thorkell the Tall and Erik of Hlathir, the Norwegian earl.

The English were divided. Æthelred was old and ill, and his son Edmund was in open quarrel with him, having seized lands in the Five Boroughs of the north Midlands. The powerful ealdorman of Mercia, Eadric Streona, whose nickname means “the Acquisitive” or “the Grasping”, changed sides and joined Cnut with 40 ships. Wessex soon submitted to the Danes.

The war of 1016

Æthelred died in London on 23 April 1016. The councillors and citizens in London chose Edmund as king, while a larger group of English nobles and churchmen meeting at Southampton recognised Cnut. The kingdom now had two rival kings.

Edmund earned his nickname “Ironside” through a remarkable campaign. During the summer he fought the Danes at Penselwood in Somerset and at Sherston in Wiltshire, relieved London from siege, won a victory at Brentford and drove the Danes from Kent after a battle at Otford. Eadric Streona then switched sides again and rejoined Edmund.

Cnut’s army, having raided into Mercia, was returning towards its ships when Edmund caught up with it at Assandun in Essex on 18 October 1016. According to the Anglo-Saxon Chronicle, Eadric fled with his men early in the battle, as he had done before, and the English army was crushed. Among the dead were Ulfcytel of East Anglia, Ealdorman Godwine, Bishop Eadnoth of Dorchester and Abbot Wulfsige of Ramsey. The Chronicle says that “all the nobility of England” was destroyed there.

The site of Assandun is uncertain. Most historians favour Ashingdon in south-east Essex, but Ashdon in the north-west of the county has also been proposed.

Division and Edmund’s death

Even after Assandun, Edmund was not finished. The two kings met at Alney, an island in the River Severn near Deerhurst in Gloucestershire, and agreed to divide the kingdom. Edmund kept Wessex, while Cnut took Mercia and the lands north of the Thames.

The arrangement lasted only weeks. Edmund died on 30 November 1016, probably in London. Contemporary sources do not say how; later writers suggested murder, but this is unproven. Cnut was accepted as king of all England at the start of 1017.

Securing England

Cnut divided England into four great earldoms. He kept Wessex for himself at first, gave East Anglia to Thorkell the Tall, Northumbria to Erik of Hlathir and Mercia to Eadric Streona. At Christmas 1017 Eadric was executed, along with several other English nobles thought to be dangerous. Edmund’s infant sons were sent abroad and eventually reached Hungary.

In July 1017 Cnut married Emma of Normandy, Æthelred’s widow. The marriage linked him to the old dynasty and to Normandy, and Emma became an influential queen. Cnut also kept his earlier partner, Ælfgifu of Northampton, the mother of his sons Sweyn and Harold Harefoot.

In 1018 Cnut raised an enormous tax to pay off his fleet: 72,000 pounds from the country and 10,500 pounds from London, according to the Chronicle. Most of the army then returned home, keeping only a fleet of 40 ships. A meeting at Oxford the same year confirmed that English law would continue, and Archbishop Wulfstan of York drafted law codes for the new king.

Rule and reputation

Cnut’s reign in England was largely peaceful. He governed through a mix of English and Scandinavian earls, kept English institutions and the English coinage, and became a generous patron of the Church. He visited the shrines of English saints and gave gifts to monasteries that his own countrymen had once plundered.

His law codes, largely drafted by Wulfstan, restated older English laws and stressed the duties of a Christian king, including protection of the Church, the poor and widows. Scandinavian influence appeared in the language of government, in the use of the word “earl” (from Old Norse jarl) and in the royal bodyguard of housecarls.

Under Cnut the rise of new English families, especially that of Godwin, reshaped the aristocracy. This would matter in 1066, when Godwin’s son Harold became king.

The North Sea Empire

Cnut’s brother Harald died around 1018, and Cnut became king of Denmark as well. He defended his position against Norway and Sweden at the Battle of the Holy River (Helgeå) around 1026, where the outcome is still debated.

In 1027 Cnut travelled to Rome to attend the coronation of Emperor Conrad II at Easter. His presence at the ceremony, alongside King Rudolf III of Burgundy, showed that a Danish ruler who had once been a Viking leader was now accepted among the leading Christian monarchs of Europe. He used the meeting to win lower tolls for English and Scandinavian pilgrims and merchants and a reduction in the payments English archbishops made for their pallium, the vestment of their office. A letter he sent home describing these gains survives.

In 1028 Cnut drove King Olaf Haraldsson out of Norway with the support of Norwegian chieftains and was proclaimed king there. Olaf’s attempt to return ended in his death at the Battle of Stiklestad in 1030. Around 1031 Cnut also received the submission of Malcolm II, king of Scots, and two other northern rulers, one of whom was probably Macbeth.

After Cnut

Cnut died at Shaftesbury on 12 November 1035 and was buried at Winchester. His empire did not outlive him. Norway rose against his son Sweyn and Ælfgifu and accepted Olaf’s son Magnus. In England, Harold Harefoot ruled from 1035 to 1040, followed by Harthacnut, Cnut’s son with Emma, until his death in 1042. The English throne then passed back to the old line in the person of Edward the Confessor, whose death without children led to the crisis of 1066.

Key people

• Cnut (c. 990s–1035), son of Sweyn Forkbeard, king of England, Denmark and Norway.
• Edmund Ironside (died 1016), son of Æthelred II, king of England from April to November 1016.
• Eadric Streona, ealdorman of Mercia, famous for changing sides; executed in 1017.
• Emma of Normandy, queen to both Æthelred and Cnut; she later commissioned the Encomium Emmae Reginae, a work praising her family.
• Thorkell the Tall, Danish war leader who served both the English and Cnut.
• Godwin, an English nobleman who rose under Cnut to become Earl of Wessex and father of the future King Harold II.

Myths and facts

Myth: Cnut arrogantly ordered the tide to go back. The story, first told by Henry of Huntingdon in the twelfth century, makes the opposite point: Cnut showed his flatterers that his power was limited and only God’s was not.

Myth: Cnut was a pagan Viking. Cnut was a Christian, as was his father, and presented himself as a pious Christian king.

Fact: his conquest relied on English divisions. Eadric Streona’s changes of side, the split between Æthelred and Edmund and the willingness of many nobles to accept Cnut were as important as Danish military strength.

By the numbers

Timeline

• 1014, 3 February: Sweyn dies; Cnut is chosen by the fleet but withdraws to Denmark.
• 1015, late summer: Cnut invades England; Eadric Streona joins him.
• 1016, 23 April: Æthelred II dies; Edmund Ironside is chosen king in London.
• 1016, 18 October: Cnut defeats Edmund at Assandun.
• 1016, 30 November: Edmund dies; Cnut becomes sole king.
• 1017, July: Cnut marries Emma of Normandy.
• c. 1018–1019: Cnut becomes king of Denmark.
• 1027: Cnut attends Conrad II’s imperial coronation in Rome.
• 1028: Cnut becomes king of Norway.
• 1035, 12 November: Cnut dies at Shaftesbury.

Why it matters

Cnut’s conquest made England, for nearly two decades, the heart of a Scandinavian empire spanning the North Sea. It showed how fragile late Anglo-Saxon England had become, brought new families like the Godwins to power and set the stage for the succession struggles that ended at the Battle of Hastings in 1066.