by Susan Flantzer
© Unofficial Royalty 2026
Olaf I Tryggvason, King of Norway and Tyra Haraldsdatter of Denmark; Credit – Wikipedia from “History of Denmark, Norway and Sweden with 253 Illustrations in Woodcuts” by Danish historian Niels Bache (1841 – 1895)
Born circa 972, Tyra Haraldsdatter of Denmark was the daughter of Harald I Bluetooth, a Viking warrior, who reigned as King of Denmark circa 958 to 986, and also reigned as King of Norway circa 970 to 986, unifying Denmark and Norway in the tenth century.
Harald’s first wife was named Gunhild (circa 936 – 965) and was probably the mother of Sweyn Forkbeard, King of Denmark, Norway, and England. Besides Gunhild, Harald Bluetooth had two other wives, Tove of the Obotrites and Gyrid Olafsdottir of Sweden. Harald had three other children besides Sweyn, but it is not certain which of his wives were their mothers. See Unofficial Royalty: Wives of Harald I Bluetooth, King of Denmark and Norway: Gunhild, Tove of the Obotrites, and Gyrid Olafsdottir of Sweden.
Harald’s other children below were either Tyra’s full siblings or half siblings:
Tyra first married Styrbjörn Starke, Crown Prince of Sweden, a son of King Olof Björnsson of Sweden. This marriage was part of a political alliance negotiated between Tyra’s father, Harald I Bluetooth, King of Denmark and Norway, and Styrbjörn Starke’s father, King Olof Björnsson of Sweden. At the same time, Tyra’s father, Harald Bluetooth, married, as his third wife, Gyrid Olafsdottir of Sweden, the daughter of King Olaf Björnsson of Sweden. Styrbjörn Starke died in the 986 Battle of Fýrisvellir, fighting with his uncle, King Eric the Victorious of Sweden, for the throne of Sweden.
Tyra, herself, arranged to marry Olaf I Tryggvason, King of Norway, as his fourth wife, which displeased her brother Sweyn Forkbeard, and he refused to pay her dowry to Olaf. Olaf set out to seek allies for a war against Denmark. On September 9, 1000, the Battle of Svolder, a large naval battle was fought in the western Baltic Sea between King Olaf I of Norway and his former ally, Sweyn Forkbeard, King of Denmark, who had allied with Olof Skötkonung, King of Sweden and Eirik Hákonarson, Jarl of Lade. Together, the three allies ambushed King Olaf I. His ship, the Long Serpent, was overpowered, and King Olaf I of Norway was defeated.
The Danish sources reported that when King Olaf I of Norway knew all was lost, he threw himself into the sea, “the end befitting his life”, according to the German chronicler Adam of Bremen. The Danish chronicler Saxo Grammaticus says that Olaf preferred suicide to death at the hands of the enemy and jumped overboard in full armor. However, some sagas suggest that Olaf made his way to the shore, perhaps by swimming or with the help of angels, but a rescue by one of the ships present is more likely. After his supposed escape, Olaf sought salvation for his soul abroad, perhaps joining a monastery.
There are no known surviving children from either of Tyra’s marriages, although some sources say she had two sons with King Olaf I, who died young. After 1000, the year her husband died in battle, Tyra disappears from historical sources. Some genealogical sources suggest she died in Norway around 1000 AD and was possibly buried there. There are also suggestions that Tyra died by suicide from starvation after receiving news of King Olaf I’s death in battle.
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Works Cited
- Bidragsydere til Wikimedia-projekter. (2015). Thyra Haraldsdatter. Wikipedia.org; Wikimedia Foundation, Inc. https://da.wikipedia.org/wiki/Thyra_Haraldsdatter
- Bidragsytere til Wikimedia-prosjektene. (2006). Tyra Haraldsdatter. Wikipedia.org; Wikimedia Foundation, Inc. https://no.wikipedia.org/wiki/Tyra_Haraldsdatter
- Flantzer, Susan. (2025). Harald I Bluetooth, King of Denmark and Norway | Unofficial Royalty. Unofficialroyalty.com. https://www.unofficialroyalty.com/harald-i-bluetooth-king-of-denmark-and-norway/
- Flantzer, Susan. (2019). Olaf I Tryggvason, King of Norway [Review of Olaf I Tryggvason, King of Norway]. Unofficial Royalty. https://www.unofficialroyalty.com/olaf-i-tryggvason-king-of-norway/
- Tyra Haraldsdatter.(2025). Geni.com. https://www.geni.com/people/Thyra-Haraldsdotter-Queen-of-Norway/6000000000350890514
- Wikipedia Contributors. (2025). Tyra of Denmark. Wikipedia; Wikimedia Foundation.
