Harald Bluetooth, King of Denmark

in Feb 5, 2021

It was during reign of King Harald Bluetooth that the name Denmark was used for the first time, immortalized forever in the runestones found in the city of Jelling. 

Fresco of Harald in the Roskilde Cathedral 

Harald Bluetooth, (also known as Haraldr Gormsson, Harald Blåtand Gormsen, Harald I Haraldr Gormsson, Harald Blåtand Gormsen or simply King Harald I), was born around 910. He was the son of Danish King Gorm the Old, who had his power base in Jelling, northern Jutland, and had begun to unify Denmark before his reign was over.

Harald’s father Gorm was fiercely faithful to the Allfather and all the Norse Gods, so much so that, when he invaded Friesland in 934, he demolished several Christian churches in the process. He was, however defeated shortly after by the German King Henry I (Henry the Fowler), who forced Gorm, to restore those churches and to grant toleration to his Christian subjects. King Gorm kept his word and did what he promised to King Henry, as war reparations. He died a year later, leaving his kingdom to Harald.

It is important to note that Harald’s formative years included a significant influence from his mother Thyra, who was inclined toward Christianity and may have given Harald some sympathy towards Christianity.

After inheriting the crown, Harald set out to continue his father's work of unifying Denmark under one rule, strengthening existing fortifications and building new ones. It was under his rule that the "Trelleborg" ring forts, considered among the most important remains of the Viking age, were constructed. Trelleborgs are circular in shape and contain 4 gates connected by roads pointing in each of the compass directions. To date, a total of seven trelleborgs have been found in Denmark and Southern Sweden, all of which date during a particular period between the late 10th and early 11th centuries. The majority of the forts were built during the reign of Harald Bluetooth as part of his process of fortifying Denmark against the Saxons to the South. Today, many of the Trelleborgs have been reconstructed and are now open to the public, with the fortresses currently applying for recognition as UNESCO World Heritage sites.


Trelleborg ring forts

One of the trelleborgs built by Harald is named Fyrkat, located near Hobro in Denmark. It contained sixteen identical long-houses arranged in four identical squares, some of which have been reconstructed. Perhaps what is most interesting about this particular Trelleborg however, are the archaeological digs that have occurred there, most notably that of the grave of a woman who has come to be known as the Fyrkat Witch, due to the unusual grave goods found with her body, which have lead to the belief that she was a sorceress or völva. Along with different animal bones, seeds, pieces of jewelry and articles of clothing that were found in the grave, the most fascinating find was that of an iron staff, which is believed to be used in divination rituals. (read more about the völva here)


The Goddess Freyja, who taught Seidr Magic to the first Volvas and to Odin himself 

During his reign Harald supported religious tolerance, allowing Bishop Unni of Bremen and Benedictine monks from the Abbey of Corvey to preach in Jutland. Harald and the bishop developed a cordial working relationship.

Sources disagree about Hatalds baptism, with some claiming that he did not agree to get baptized himself, and some claiming that he was baptized by a priest called Poppa or Poppo, who supposedly performed a miracle in which he held red-hot metal without being burned. Regardless of his personal faith, Harald’s religious tolerance supported the spread of Christianity among the Danes.

Once he had established internal peace in Denmark, Harald was in a position to take an interest in external matters, especially those concerning his blood relatives. His sister, Gunnhild, fled to Harald with her five sons when her husband, King Erik Bloodaxe of Norway, was killed in battle in Northumberland in 954. Harald helped his nephews reclaim territories in Norway from King Hakon. He was met with serious resistance at first and Hakon even succeeded at invading Jutland, but Harald was ultimately victorious when Hakon was killed on the island of Stord.

Harald's Christian nephews took possession of their lands and, led by Harald Greycloak (the eldest nephew), they embarked on a campaign to unify Norway under one rule.

During this attempt of unification, Greycloak and his brothers were trying to force people to convert to Christianity. Greycloak and his goons routinely defiled sacrifices to the Gods and despoiled temples of worship. This created a great unrest on the common people, which made unification an unlikely prospect. During this time, Greycloak also began to forge alliances with former enemies. The aggression towards the Old Gods and the new alliances made by Greycloak did not sit well with Harald Bluetooth, to whom his nephews owed much for his aid in obtaining their lands. Harald, however, did not have much time to act, as his nephew Greycloak was soon assassinated, ostensibly by one of his former enemies, now new “allies”. Bluetooth took the opportunity to assert his rights over Greycloak's lands and was able to take control of Norway not long after.

"Gentle" coercion to convert to Christianity

Harald’s reign as King of Norway (which doesn’t correspond geographically to the modern Norway) didn’t last long though, and his tenuous control ended just a few years later during 970s.

In the meantime, Christianity had been making some notable headway in Denmark. The Holy Roman Emperor Otto the Great, who professed a deep devotion to the religion, saw to it that several bishoprics were founded in Jutland under papal authority. Due to conflicting and unsubstantiated sources, it is not clear exactly why this led to war with Harald; it may have something to do with the fact that these actions made the dioceses exempt from taxation by the Danish king, or perhaps it was because it made the territory appear to be under Otto's suzerainty. In any case, war ensued, and the exact outcome is also unclear. Norse sources maintain that Harald and his allies held their ground; German sources relate that Otto broke through the Danevirke and imposed sanctions on Harald, supposedly including making him accept baptism and evangelize Norway.

Whatever burdens Harald had to deal with as a result of this war, he showed himself to retain considerable clout in the following decade. When Otto's successor and son Otto II was busy fighting in Italy, Harald took advantage of the distraction by sending his other son, Svein Forkbeard, against Otto's fortress in Slesvig. Svein captured the fortress and pushed the emperor's forces southward. At the same time, Harald's father-in-law, the king of Wendland, invaded Brandenburg and Holstein and sacked Hamburg. The forces of the emperor were unable to counter these attacks, and so Harald reclaimed control of all of Denmark. 

Harald’s reign over Denmark lasted until c.987, when he was killed in battle against his son Svein. His body was brought back to Denmark and laid to rest in the church at Roskilde.

Sweyn and the Jomsvikings at the funeral ale of his father Harald Bluetooth. Painting by Lorenz Frølich, c. 1883–86, Frederiksborg Castle.

In addition to constructing the Trelleborg ring forts, Harald extended the Danevirk and left remarkable runestones in Jelling, Denmark.

The Jelling Stones are two of the most famous and important runestones found in Denmark. The two stones were raised by Harald Bluetooth and his father Gorm the Old respectively. The older one raised by Gorm honors the life of his wife Thyra, whilst the newer one raised by Harald, although still paying tribute to his family, is most well known for its claim that Harald converted the people and kingdom of Denmark to Christianity. Even though this supposed conversion is highly controversial, it does show the importance that Harald placed upon his his mother’s religion, well as the religion’s importance when it came to the political situation of Europe in the Early Middle Ages.


Extra facts:

The modern Bluetooth technology used to connect electronic devices was named for the ancient Viking king. According to Jim Kardach, one of the founders of Bluetooth SIG:

Harald had united Denmark and Christianized the Danes! It occurred to me that this would make a good codename for the program. At this time I also created a PowerPoint foil with a version of the Runic stone where Harald held a cellphone in one hand and a notebook in the other and with a translation of the runes: 'Harald united Denmark and Norway' and 'Harald thinks that mobile PC’s and cellular phones should seamlessly communicate.'"

The designers chose the name specifically because of the ‘unification’ context of his legacy, with the Bluetooth technology intended to unite all computer devices. The Bluetooth symbol is a combination of the runes for H and B.





The Editors of Encyclopaedia Britannica. “Harald I.” Encyclopædia Britannica. 4 Apr. 2018.

The Jelling Stone.” National Museum of Denmark.

Legendary Harald 'Bluetooth' King Of Denmark - 'Who Made The Danes Christian.'" Ancient Pages, 16 May 2017.

Bluetooth: Why Modern Tech Is Named After Powerful King of Denmark and Norway.” Ancient Origins, Ancient Origins, 20 Jan. 2017.

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