Who was Sweyn Forkbeard?

Sweyn Forkbeard (also Swein or Svein) was the son of Harold Bluetooth, the first Christian king of Denmark, who had substantially enlarged the Danish kingdom and been accepted as overlord in Norway. Eager to wield power himself, Sweyn rebelled against his father in AD 987, and drove him into exile.


Such was the stability of the realm that Harold had created that Sweyn was free to lead raids on England himself, without having to worry about his security at home. And his campaign enjoyed the support not only of his own retainers but also of other leading men from Denmark and elsewhere in Scandinavia, who hoped to profit from the treasures he would win.

Sweyn’s nickname, Forkbeard, is first recorded in a chronicle from Roskilde, compiled about 1140. Most medieval accounts of his career followed the lead given by a German chronicler, Adam of Bremen, who denigrated Sweyn for failing to recognise the authority of the German emperor and not acknowledging the ecclesiastical authority of the archbishop of Hamburg-Bremen.

A more positive picture is offered in a text in praise of Emma of Normandy, widow of Æthelred the Unready, who went on to marry Cnut, Sweyn’s son. There Sweyn is praised as a fortunate, generous and religious king.

How did Sweyn Forkbeard become king of England?

Around one thousand years ago, the king of Denmark (and lord also over Norway and Sweden) invaded England with a large fleet. After a brief campaign, he secured the submission of all the English people apart from the inhabitants of London. When, as a near-contemporary English chronicler reported, “all the nation regarded him as full king”, the citizens of London finally capitulated and submitted, giving the Dane hostages, “for fear that he would destroy them”.

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That king was Sweyn Forkbeard. His swift conquest sent the Anglo-Saxons’ native ruler, Æthelred (nicknamed ‘the Unready’) into exile in Normandy, leaving his English subjects to pay a large tribute and supply their conqueror and his army with provisions.

How could a foreign adventurer have brought such an abrupt end to the rule of the descendants of Alfred the Great? How could he have reversed the victory Alfred had won over the ninth-century Vikings, and reduced England to a subject realm within a Scandinavian empire?

The story of Sweyn’s conquest of England goes back to the AD 990s, to one of the most celebrated episodes in early English military history, reported laconically in the Anglo-Saxon Chronicle, but commemorated in a famous Old English poem: The Battle of Maldon. In the summer of 991, a fleet of more than 90 Viking ships landed in Kent, sailed to Ipswich and, after sacking that town, came into the estuary of the Blackwater river in Essex.

Facing them on the other shore stood the ranks of the English army led by the Ealdorman of Essex, Byrhtnoth. When a Danish messenger called across the water to urge the English to make peace and “buy off this onslaught of spears with tribute-money”, so that they need not “join battle so grievously”, Byrhtnoth stepped forward to speak in response:

Sea raider, can you hear what this army is saying?

They intend to give all of you spears

as tribute, deadly points and tried swords,

payment in war-gear, which will be of no

benefit to you in battle.

Messenger of the seamen, report back!

Tell your people a much less pleasing tale

that here stands with his company an earl

of unstained reputation,

who intends to defend this homeland,

the kingdom of Æthelred, my lord’s

people and his country. They shall fall

the heathens in battle.

(Battle of Maldon, lines 45–54)

Determining that the “grim game of battle” would arbitrate between them before the English would pay tribute, Byrhtnoth ordered his men to pick up their shields and walk to stand on the edge of the river, where the flood tide flowed, separating the two forces.

Only when the waters receded could the seaborne attackers try to take the causeway, which bold Englishmen defended resolutely, refusing to take flight from the ford.

The perfidious Vikings (as the poem portrayed them) tricked their way into getting Byrhtnoth to yield some ground; he then paid the ultimate price for that act of pride, as the poet saw it, of conceding the Danes too much land. Byrhtnoth fell in the battle, with his last breath commending his soul to the Lord of hosts and of angels.

Hateful visitors

The Maldon poet contrasted the heroism and dedication of Byrhtnoth and those who fell with him – loyal followers of a devout lord – with the disloyal and ungrateful cowards who fled the battlefield on their lord’s death, instead of sacrificing their own lives to avenge him. Danes (“the hateful visitors”) appear as arrogant in their demand for tribute before a blow has been struck; they use guile to gain ground on the English side of the causeway. English valour and moral courage lie at the heart of the poet’s message, but the military prowess of the “fierce” Vikings is never concealed.

Although the poem did not name any of the hostile army, the Anglo-Saxon Chronicle credited Olaf (Tryggvason) with leading the force that attacked England in 991, implying that he fought at Maldon. But an independent source mentions the involvement of an Essex nobleman in a “treacherous plan that Sweyn should be received in Essex when first he came there with a fleet”.

This suggests that Sweyn, not Olaf, took the command. Newly established as king in Denmark, with the substantial power and resources of that realm behind him, Sweyn made a more plausible leader of this invading force than did the Norwegian adventurer Olaf. He would prove a formidable foe.

After a period of relative peace, Vikings had begun again to attack English shores before Sweyn and Olaf arrived in 991. Sweyn’s personal involvement represented a new threat: Denmark’s ruler had his eye on the material resources of England, one of the richest kingdoms of its day.

Scandinavian adventurers had sought new lands and opportunities in western Europe since the ninth century, but never before had the Danish king himself led their raids. Sweyn’s ability to spend so much time on overseas expeditions offers an insight into the security of his power at home. The plunder he gathered in England helped to bolster both his resources and his reputation, strengthening his position on both sides of the North Sea.

Spreading misery

Defeated at Maldon, the English paid tribute to the Danes. Further Danish victories followed in the next three years, with attacks on East Anglia, Lindsey, Northumbria, London, Essex, Kent, Sussex and Hampshire until the English again paid tribute.

At this point, in 994, the English king Æthelred succeeded in separating Sweyn and Olaf by sponsoring Olaf at his confirmation and giving him royal gifts. In return, Olaf promised never to come back to England in hostility, but took his new wealth to Norway and seized the throne.

This forced Sweyn back to Scandinavia to counter the threat to his own realm. While the Danish king sought to reassert control at home (defeating and killing his Norwegian rival in 999), Viking armies continued to harry England, levying large tributes and causing significant misery.

Sweyn first reappears in the English chronicle record when leading the army in an attack on Exeter in 1003, but he may have returned to England as early as 1000. In 1004 he came with his fleet to Norwich, and burned the town down. Fierce fighting near Thetford brought Sweyn another victory and it seemed no man could defeat him. Then in 1005 a famine struck England, one so bad that the chronicler wrote that “no man ever remembered one so cruel”. Sweyn was forced to take his fleet back to Denmark.

The chronicler, writing from London some time after the events, during the reign of Sweyn’s son Cnut, laid the blame for the recurrent English defeats firmly on the English leadership. To the chronicler’s mind, the incompetence, indecision and cowardice of those in power weakened the morale and determination of the rank-and-file troops, who often crumbled on the battlefield without offering real resistance.

So weak were England’s defensive responses that the Danes went about as they pleased: “Nothing withstood them, and no naval force nor land force dared go against them, no matter how far inland they went” (Anglo-Saxon Chronicle).

Even Æthelred’s drastic strategy of ordering the massacre of all Danish men in England on St Brice’s Day in 1002 did little to turn the tide of Danish victory, serving only to heighten the population’s fears.

Listen | Dr Benjamin Savill outlines his new theory that the massacre may have been planned specifically for the feast day of the exiled St Brice on this episode of the HistoryExtra podcast

Although Sweyn stayed in Denmark after his return in the year of the great famine in England (1005), his absence brought no respite to the English. The arrival in 1009 of the “immense raiding army”, led by Thorkell the Tall, represented a turning point in Æthelred’s reign.

Whether, as one source favourable to Sweyn maintained, Thorkell came as the agent of Sweyn or (as is more plausible) he led an independent band of warriors, drawn from across Scandinavia, Thorkell’s tactics and military prowess proved more than a match for English defences. Between 1009 and 1012, his army devastated great swathes of England.

As the chronicler wrote: “All these disasters befell us through bad policy, in that they were never offered tribute in time, nor fought against; but when they had done most to our injury, peace and truce were made with them. And for all this truce and tribute, they journeyed none the less in bands everywhere, and harried our wretched people and plundered and killed them.”

From an English perspective, the nadir of Thorkell’s campaign came in 1012 following the fall of the city of Canterbury when, on 19 April, his army shamefully put to death Ælfheah, archbishop of Canterbury. In the aftermath of the archbishop’s martyrdom, Thorkell and 45 ships from his army changed sides to ally with Æthelred, promising to defend England.

1013: the year the Vikings conquered England

In 1013, King Sweyn arrived with his fleet at Sandwich in Kent. He might (as one source maintained) have wanted to punish Thorkell for changing sides. But a close connection between Sweyn and Thorkell cannot be proven, and other considerations motivated the Danish king, including the desire to now conquer England.

From Sandwich, Sweyn sailed quickly round East Anglia, into the mouth of the Humber and along the Trent until he reached Gainsborough. Without a fight, Earl Uhtred and all the Northumbrians, the people of Lindsey and of the Five Boroughs and all the Danish settlers north of Watling Street submitted to him. This diplomatic victory gave Sweyn a power base from which to attack Thorkell and Æthelred in the south.

Having provisioned his army, and equipped it with horses, Sweyn left his son Cnut in charge in Northumbria and crossed Watling Street. Then he allowed his army to do whatever damage it would, intending to subdue the English by fear. His strategy worked. The citizens of Oxford submitted to him and gave him hostages; so did the men of Winchester.

Only London refused to yield, its citizens resisting because King Æthelred and Thorkell were inside its walls. So Sweyn turned away to Wallingford, crossed the Thames and went to Bath, where he stayed with his army. All the western ‘thegns’ (noblemen) came to submit to him and gave him hostages.

Now, as the chronicler wrote, “all the nation regarded him as full king”. So it was that the men of London also submitted for fear of what he would do to them. And Sweyn demanded full payment and provisions for his army that winter. Yet, despite it all, the chronicler lamented, “his army ravaged as often as they pleased”.

King Æthelred escaped to the Isle of Wight where he spent Christmas, and then went into exile with his wife’s people in Normandy. For one short winter, Sweyn, the king of Denmark and overlord of much of Scandinavia, added England to his empire. But on 3 February 1014, Sweyn died, and the fleet elected Cnut as king. The English then thought better of their own king, their natural lord and begged him to return, “if he would govern them more justly than he did before”.

It would take two more years of heavy fighting, the death of Æthelred (in April 1016) and of his son Edmund Ironside at the end of November that same year, before Cnut would succeed to the whole kingdom of the English and so initiate a period of Danish rule.

Cnut’s ultimate victory owed much to the persistence and military prowess of his father, Sweyn. From the perspective of 1013, it was clear that Byrhtnoth and his companions at Maldon had fallen to the superior military and tactical strength of the most successful king of the Viking age.

Sarah Foot is the regius professor of ecclesiastical history at Christ Church, Oxford. Her books include Æthelstan: The First King of England (Yale, 2011)


This article was first published in the August 2013 issue of BBC History Magazine