Founder of the House of Estridsen

Sweyn was born in England, as the son of Ulf Thorgilsson and Estrid Svendsdatter, the latter of whom was the daughter of King Sweyn I Forkbeard and sister of Kings Harald II and Canute the Great. Sweyn grew up a military leader, and served under king Anund Jacob of Sweden for a time. He pillaged the Elbe-Weser area in 1040, but was caught by the Archbishop of Hamburg-Bremen, who released him shortly thereafter.

Svend was made a jarl under Danish king Harthacnut (the two were first cousins), and led a campaign for him against Norway, but was beaten by Magnus I of Norway. When Harthacnut died in 1042, Magnus claimed the Danish throne and made Svend the jarl of Jutland. In 1043, Sweyn fought for Magnus at the Battle of Lyrskov Heath at Hedeby, near the present-day border of Denmark and Germany. Sweyn won a great reputation at Lyrskov Heath, and had the Danish nobles crown him king in Viborg in Jutland. He was defeated by Magnus on several occasions, and had to flee to Sweden. Eventually he managed to return and establish a foothold in Scania.

The war between Magnus and Sweyn lasted until 1045, when Magnus' uncle Harald Hardrada returned to Norway from exile. Harald and Sweyn joined forces, and Magnus decided to share the Norwegian throne with Harald. In 1047 Magnus died, having stated on his deathbed that his kingdom would be divided: Harald would get the throne of Norway, while Sweyn would be king of Denmark. Upon hearing of Magnus' death Sweyn said, "Now so help me God, I shall never yield Denmark".

Death

King Sweyn died at the royal estate Søderup, 10 kilometres (6.2 mi) west of Åbenrå at the Little Belt strait. The Danish chronicles inaccurately date his death to 1074, but it is known that he received and answered letters in 1075 and died in 1076. The king's body was carried to Roskilde Cathedral where he was interred in a pillar of the choir next to the remains of Bishop Vilhelm (who was the actual person who died in 1074). Later he was called the "father of kings" because five of his fifteen sons became kings of Denmark.

He was the last Viking ruler of Denmark and an ancestor of all subsequent Danish kings. The remains of other Danish kings are also entombed in Roskilde Cathedral. According to the saga, Sweyn's mother was entombed inside a pillar across from the chapel. However, analysis of mitochondrial DNA proved that this person was not the king's mother.

Legacy

One of the legacies of King Sweyn was a fundamental change in Danish society which had been based on whether a person was free or a bondsman. Sweyn is often considered to be Denmark's last Viking king as well as the first medieval one. A strengthened church in alliance with the land-owning noble families begin to pit their power against the royal family. The peasants were left to fend for themselves.

Sweyn built a strong foundation for royal power through cooperation with the church. He completed the final partition of Denmark into dioceses by corresponding directly with the pope, bypassing the Archbishop of Hamburg-Bremen. During his reign hundreds of small wooden churches were built throughout the kingdom; many were rebuilt in stone in the 12th century. Sweyn sought to create a Nordic Archbishopric under Danish rule, a feat which his son Eric I accomplished.

Sweyn seems to have been able to read and write, and was described as an especially educated monarch by his personal friend Pope Gregory VII. He is the source of much of our current knowledge about Denmark and Sweden in the 9th and 10th centuries, having told the story of his ancestry to historian Adam of Bremen around 1070.

Family

Sweyn's first marriage was to Gyda of Sweden, daughter of king Anund Jacob of Sweden. His second marriage, in 1050, was to Gunnhildr Sveinsdóttir, the stepmother of Gyda. The Archbishop of Hamburg-Bremen ordered that the union be dissolved, which was effectuated by Pope Leo IX. According to Adam of Bremen, Sweyn had a certain "Tora" at his court. Historian Sture Bolin argues that this "Tora" is actually Tora Torbergsdatter, the mother of king Olaf III of Norway, linking this to a passage about a king marrying the mother of a king named Olof. He took one mistress after another during his life. Sweyn fathered at least 20 children, of whom only one was born in wedlock.