Harald "Bluetooth" Gormsson (Old Norse Haraldr blátǫnn, Danish Harald Blåtand; c. 910 in Denmark; † 1 November 985/987 in Jomsburg) was king of Denmark (c. 958/964-985/987) and of Norway (c. 970-ca. 975). He belonged to the House of Jelling.
Harald was a son of Gorm the Old and his wife Thyra Danebod. After the death of his father, Harald succeeded him as king. The relevant date is disputed in research.
In part, based on source statements, the time around 936 is assumed, but dendrochronological examinations of a wooden chamber in Gorm's presumed grave in Jelling indicate that Gorm died in 958 and Harald thus succeeded him in that year.
Harald invaded Normandy several times as a Viking leader, where he supported Richard the Fearless in 945 by capturing Louis IV and forcing him to recognize Richard's rule.
Harald recognized Otto I's suzerainty in 948 and founded the bishoprics of Aarhus, Ripen and Schleswig, beginning the Christianization of Scandinavia. In 950 he founded Jomsborg (also known as Julin, Jumne, Wollin) in what later became Pomerania. His main residence was probably in Jelling under the present church.
According to a report by Widukind of Corvey, Harald was baptized at the Poppostein around 960, after the priest Poppo had convinced him of Christianity by a miracle.
In 963 and 967 the rich Wolin and thus also the Jomsburg were attacked by Prince Mieszko I (first mention of the Polans), but not conquered. It is documented that Wichmann II also fought there against the Poles in 963 and 967 and fell in 967, which indicates cooperation.
In 974 he invaded Holstein after the death of Otto I. In a counterattack by Otto II, he lost Schleswig to the emperor.
Harald allied himself with the sons of Erik Bloodaxe, who had been expelled by Håkon the Good. After the death of Håkon the Good, he occupied southern Norway and became king of Norway. Under his rule, he appointed Erik Bloodaxe' sons as jarls, including Harald Gråfell.
These killed Sigurd Ladejarl, the former ally of Håkon the Good. Thus began the long enmity between Harald Hårfagre's family and the Ladejarls. But when the latter became too autocratic, Harald Bluetooth changed partners and allied himself with Haakon Sigurdsson, son of the murdered Sigurd Ladejarl, and the latter became his vassal. In 983 Harald regained Schleswig, which had been lost in 974.
Harald had united Denmark under one crown for the first time. However, an inheritance dispute with his son Sven Forkbeard led the latter to rebel against him. A dispute fought on the Baltic Sea between father and son, the legendary naval battle of Helgenes around 986, probably near Bornholm, ended in favor of the king's son Sven, as he was supported by the Jomsvikings.
According to Norse sources, such as the Jómsvíkinga saga, Knýtlinga saga and Heimskringla, during a night pause in the battle on land, the king was hit by an arrow from ambush, which wounded him severely.
Harald Bluetooth escaped from the battle with faithful and saved himself to the southern part of the Baltic coast in what later became Pomerania. He died in Jomsborg or Jumne on All Saints' Day 985 or 986. His son succeeded him as king of Denmark. Harald's body was transferred to Roskilde to the church he built, according to the report of Adam of Bremen.
The origin of the nickname "Bluetooth" or "Blacktooth" is unclear and therefore the subject of numerous speculations and folk etymologies. That the name referred to the color of the king's teeth is controversially discussed.
The first component of the compound can certainly be traced back to the Old Norse color designation blár, which stands for "dark blue" as well as for "black" or "lead-colored."
Uncertainty exists concerning the component -tönn "tooth". Plausibly, it seems to be a so-called Heiti metaphor for a sword. Other historians assume that it is to be connected with the word þegn "freisasse, subject; dagger" (cf. English thane and chieftain).
However, the nickname can also be taken literally. A dead tooth nerve leads to a dark discoloration of the tooth, which can be very noticeable, especially in the area of the front teeth. The epithet "Bluetooth" or "black tooth" can therefore certainly describe such a conspicuous feature.
The Bluetooth technology standard for computers, cell phones and their peripherals, was named after Harald Bluetooth and is a tribute to his abilities to unite several principalities into one great kingdom. The logo shows the initials HB in the form of a monogram (bindrune) of the runes Hagalaz and Berkana.
