Anund Jacob

Legend says that Estrid of the Obrotrites was taken back to Sweden from a war in the West Slavic area of Mecklenburg as a war-prize.

She was most likely given by her father, a tribal chief of the Polabian Obotrites, as a peace offering in a marriage to seal the peace with King Olof Skötkonung, and she is thought to have brought with her a great dowry, as a great Slavic influence is represented in Sweden from her time, mainly among craftsmen.

Her husband also has a mistress, Edla, who comes from the same area in Europe as herself, and who was possibly taken to Sweden at the same time.

The king treats Edla and Estrid the same way and has given his son and his two daughters with Edla the same privileges as the children he has with Estrid, though it was Estrid he had married and made Queen.

Queen Estrid is baptized with her husband, their children and large numbers of the Swedish royal court in 1008, when the Swedish royal family converts to Christianity, although the king promises to respect the freedom of religion—Sweden is not to be Christian until the last religious war between Inge the Elder and Blot-Sweyn of 1084-1088.

A new had war erupted between Norway and Sweden when Olaf II of Norway reestablished the Norwegian kingdom.

Many men in both Sweden and Norway try to reconcile the kings.

Olof's cousin, the earl of Västergötland, Ragnvald Ulfsson and the Norwegian king's emissaries Björn Stallare and Hjalti Skeggiason had arrived in 1018 at the thing of Uppsala in an attempt to sway the Swedish king to accept peace and as a warrant marry his daughter Ingegerd Olofsdotter to the king of Norway.

The Swedish king had been greatly angered and threatened to banish Ragnvald from his kingdom, but Ragnvald was supported by his foster-father Thorgny Lawspeaker.

Thorgny had delivered a powerful speech in which he reminded the king of the great Viking expeditions in the East that predecessors such as Erik Anundsson and Björn had undertaken, without having the hubris not to listen to their men's advice.

Thorgny himself had taken part in many successful pillaging expeditions with Olof's father Eric the Victorious and even Eric had listened to his men.

The present king wants nothing but Norway, which no Swedish king before him had desired.

This displeases the Swedish people, who are eager to follow the king on new ventures in the East to win back the kingdoms that paid tribute to his ancestors, but it is the wish of the people that the king make peace with the king of Norway and give him his daughter Ingegerd as queen.

Thorgny had finished his speech by saying: if you do not desire to do so, we shall assault you and kill you and not brook any more of your warmongering and obstinacy.

Our ancestors have done so, who at Mula thing threw five kings in a well, kings who were too arrogant as you are against us.

Olof, however, in 1019 instead marries his daughter Ingegerd-Irene to the powerful Yaroslav I the Wise .

An impending war is settled when Olof agrees to share his power with his son Anund Jacob.

Olof is also forced to accept a settlement with Olaf II of Norway at Kungahälla, who already had been married (unbeknownst to Olof) with Olof's daughter, Astrid, through the Geatish jarl Ragnvald Ulfsson.

The death of Olof Skötkonung is said to have taken place in the winter of 1021–1022.

According to a legend, he was martyred at Stockholm after refusing to sacrifice to pagan gods.

King Cnut of England and Denmark seeks to restore Danish rights in Norway, lost in 1016 upon the ascension of native Olaf Haraldsson as monarch.

Olaf and King Anund Jacob of Sweden, seeing the combined Anglo-Danish kingdom as a threat—Cnut's father Sweyn had asserted power over both their countries—take advantage of Cnut's being in England to attack the Danes in the Baltic Sea in 1025 or 1026, and are joined by Ulf Jarl, Cnut's Danish regent, and his brother.

Ulf Jarl is the son of Thorgils Sprakalägg, who is claimed to have been the son of Styrbjörn the Strong, a scion of the Swedish royal house, by Tyra, the daughter of king Harald Bluetooth of Denmark.

However, Thorgils' parentage may have been invented to glorify the royal dynasty founded by Ulf's son, Sweyn Estridson.

Ulf had joined Cnut’s expedition to England.

He had married Cnut's sister Estrid in about 1015 and was appointed the Jarl of Denmark, which he rules when Cnut is absent.

He is also the foster-father of Cnut's son Harthacnut.

When the Swedish and Norwegian kings attack Denmark, Ulf persuades the freemen, who are discontent at Cnut's absentee rule, to elect Harthacnut king.

This is a ruse on Ulf's part, as his role as Harthacnut's guardian will make him the ruler of Denmark.

When Cnut learns what has happened, he returns to Denmark and confronts his enemies at the Battle of the Helgeå, where the Swedish and the Norwegian navies led by kings Anund Jacob and Olaf II lie in wait up a river for the navy of King Cnut, which is commanded by Ulf Jarl.

Cnut's navy is massive and his own ship is said to have been eighty meters long.

The Swedish and the Norwegian kings had ordered a large dam made of peat and lumber to built on the river.

When the Danish navy sails in, the water is released and a great many Danes and Englishmen drown in the deluge.

However, Cnut's men are apparently able to win the battle.

The outcome is disputed, but Cnut comes out best; Olaf flees and the threat to Denmark is dispelled.

The apparent victory leaves Cnut as the dominant leader in Scandinavia.

The battle is retold in skaldic poetry and in sources such as the Danish Gesta Danorum by Saxo Grammaticus and the Icelandic Saga of Olaf the Holy by Snorri Sturluson.

Opinions are divided on whether the location was at Helgeå in Uppland or the Helgeå of eastern Skåne.

In the Anglo-Saxon Chronicle, the battle is dated to 1025 and the Swedes won the battle.

Cnut claims to rule "part of Sweden" together with England, Denmark, and Norway.

At some time after the Battle of the Helgeå, he subjugates the core provinces of Sweden around Lake Mälaren, where he has his own coins minted either in the capital, Sigtuna, or in Lund, at this time part of Denmark, with the inscription CNVT REX SW ("Cnut King of the Swedes").

Western Götaland or Blekinge have been suggested.

It is probably an overlordship more than actual rule; Cnut does not have to be present in Sweden to order the minting of coins.

Coins are also minted asserting he rules Ireland, and Swedish history at this early date is so uncertain that we can hardly be sure even of the names of the kings.

Denmark is threatened by Norway and Sweden in the 1020s, and Cnut decides in 1026 to strengthen its defenses by bringing over his eight-year-old son to be the future king under a council headed by his brother-in-law, Earl Ulf.

However, Ulf alienates Cnut by getting the Danish provinces to acknowledge Harthacnut as king without reference to Cnut's overall authority and by failing to take vigorous measures to meet Norwegian and Swedish invasions, instead waiting for Cnut's assistance.

Ulf's assistance to Cnut at the Battle of the Helgeå has not caused Cnut to forgive Ulf for his coup.

At a banquet in Roskilde, the two brothers-in-law are playing chess and start arguing with each other.

The next day, Christmas of 1026, Cnut has one of his housecarls kill Earl Ulf in Trinity Church, the predecessor of Roskilde Cathedral.

Accounts are contradictory, however.

Ulf is the father of Sweyn Estridson, and thus the progenitor of the House of Estridsen, which will rule Denmark from 1047 to 1375, and which is also sometimes, specially in Swedish sources, referred to as the Ulfinger dynasty to honor him.

Norway had been divided during the ninth century among several local kings controlling their own fiefdoms.

King Harald Fairhair had managed, mainly due to the military superiority gained by his alliance with Sigurd Ladejarl of Nidaros, to subjugate these mini–kingdoms, and by the end of the century he had created the first unified Norwegian state.

This alliance had come apart after Harald's death.

The jarls of Lade and various descendants of Harald Fairhair had spent the tenth century interlocked in feuds over power.

As well as power politics, religion also plays a part in these conflicts, as two of the descendants of Harald Fairhair, Hakon the Good and Olaf Tryggvason attempted to convert the then heathen Norwegians to Christianity.

Svein (Old Norse: Sveinn) and Erik (Old Norse: Eiríkr) of Lade had in the year 1000 taken control of Norway, being supported by the Danish King Svein.

Olaf Haraldsson, representing the descendants of Harald Fairhair, had in 1015 returned from one of his Viking trips and was immediately elected as King of Norway.

He had won the Battle at Nesjar in June 1016 against the Jarls of Lade.

Olaf Haraldsson's success in becoming King of Norway had been helped by the Danes being kept occupied with the ongoing fighting in England.

Olaf II had extended his power throughout Norway while Jarl Erik was with Cnut in England.

Cnut's enmity with him extends further back: Æthelred had returned to England in a fleet provided by Olaf.

Cnut had offered in 1024 to let Olaf govern Norway as his vassal, but after Helgeå, he had set about undermining his unpopular rule with bribes, and in 1028 sets out with fifty ships to subjugate Norway.

A large contingent of Danish ships joins him, and Olaf withdraws into the Oslo Fjord while Cnut sails along the coast, landing at various points and receiving oaths of allegiance from the local chieftains.

Finally at Nidaros, now Trondheim, he is acclaimed king at the Eyrathing, and in a few months Olaf, whose hard-line imposition of Christianity has created powerful enemies within Norway, flees to Novgorod.

Cnut, who had arrived in Denmark with a fleet in 1027, had forgiven Harthacnut his insubordination in view of his youth but had had Ulf murdered.

After driving the invaders out of Denmark and establishing his authority over Norway, he returns to England in 1028 and leaves Denmark to be ruled by Harthacnut.

Norway’s last Lade, Jarl Haakkon Eiriksson, drowns in 1029, and Cnut appoints his son Svein to rule Norway with the assistance of Ælfgifu, Cnut's first wife and Svein's mother.

Olaf makes plans to return to Norway with his army to regain his throne and the Kingdom of Norway.