Debating Harald ‘Bluetooth’: Are New Theories Dismissing the Dental Explanation?
How Gaelic and Weapon-Based Speculations Are Fueling new Investigations of Harald Gormsson's Moniker
Harald “Bluetooth” Gormsson, King of Denmark (and, at times, parts of Norway) in the late 10th century, stands as one of the most notable Scandinavian monarchs of the Viking Age. While his political and military accomplishments receive due attention in medieval sources and modern scholarship, his epithet—“Bluetooth” (Old Norse Blátǫnn or Danish Blåtand)—continues to captivate the public imagination. Indeed, in a recent conversation with my co-host of the Vikingology Podcast, Terri Barnes, we discussed some intriguing new ideas that her students have brought up in class that they found circulating on the internet, which prompted this article. Over the centuries, various theories have emerged regarding its meaning, including a literal interpretation of a discolored tooth, a possible Gaelic-language connection through his father, Gorm, and the notion that “Bluetooth” may have referred to a weapon rather than Harald himself. This article examines these theories through a brief analysis of the primary and secondary sources, shedding light on the historical context and the scholarly debates surrounding Harald’s famous moniker.
Harald’s Place in History
Harald Bluetooth was the son of Gorm the Old (d. c. 958) and his queen, Thyra. He is credited with consolidating power in Denmark, extending influence over areas in Norway, and playing a significant role in the Christianization of his realm. Primary sources that discuss Harald include runic inscriptions—most notably the Jelling stones (often referred to as “Denmark’s birth certificate”)—and the writings of Saxo Grammaticus (12th–13th century), although Saxo’s Gesta Danorum can be interpretive and literary rather than strictly factual (Saxo, Gesta Danorum, c. 12th–13th century). Adam of Bremen (11th century) also provides information about Danish kings of the period but does not dwell extensively on Harald’s epithet.
The “Blue/Discolored Tooth” Hypothesis
A common and straightforward explanation posits that Harald had an unusually colored tooth—described as blue, dark, or otherwise discolored—that earned him the nickname “Blåtand.” The literal meaning is reinforced by the Old Norse and Danish words for “blue/dark” (blå/blár) and “tooth” (tand). This line of reasoning aligns with other Viking Age nicknames thought to refer to physical traits, such as Harald Fairhair (Haraldr hárfagri) or Eric Bloodaxe (Eiríkr blóðøx). However, historians have noted that such nicknames were not always as literal as they might appear (Sawyer 2000, pp. 84–85). For example, the sobriquet “Hairy-Breeches” associated with Ragnar (Ragnarr loðbrók) is highly contested; it may signify fur trousers or be a metaphor for some distinctive personal habit. Likewise, “Ivar the Boneless” (Ívarr inn beinlausi) presents a range of interpretive challenges, from physiological differences to metaphorical connotations of flexibility or cunning (Roesdahl 1987, pp. 150–151). In this respect, while Harald’s “Bluetooth” may indicate a physical characteristic, uncertainty persists.
The Gaelic Connection: Gorm = Blue
The father of Harald, known as Gorm the Old, bears a name that, coincidentally, resembles the Gaelic word gorm, meaning “blue” or “dark blue” (Old Irish, Scottish Gaelic). While this lexical overlap has fueled speculation—suggesting a Gaelic pun or a familial tendency toward “blue” designations—most scholars maintain this resemblance is fortuitous (Sawyer 2000, pp. 54–55). In a Norse context, Gorm was a relatively common personal name; the Gaelic meaning is likely incidental. Nevertheless, the correspondence between Gorm and gorm lends itself to modern interpretations that weave a possible Gaelic layer into the story of Harald’s nickname.
The Sword Theory
A less common hypothesis proposes that “Bluetooth” may have referred to Harald’s sword—potentially one with a notable bluish steel sheen or a distinctive name. Viking and medieval sources (e.g., Egils saga, Grettis saga) often mention swords with proper names—“Leg-Biter,” “Gram,” and “Skofnung”—and these weapons could themselves attain legendary status. However, no direct evidence exists in Gesta Danorum, the runic inscriptions, or other extant medieval sources that “Bluetooth” designated a sword (Roesdahl 1987, pp. 112–113). Historians who have surveyed Old Norse literature and material culture, such as Else Roesdahl and Birgit Sawyer, and contributors to the journal Viking and Medieval Scandinavia, do not attribute Harald’s epithet to a named weapon. Thus, while creative speculation persists, it remains unsubstantiated by primary sources.
The Role of Technology and Modern Popularity
Harald’s name re-entered global lexicons in the 1990s when engineers developing a new wireless standard codenamed their project “Bluetooth.” Project participants chose the moniker because Harald united parts of Scandinavia, just as this technology aimed to unite different digital devices (Kardach 2008, IEEE, anecdotal references). The now-familiar Bluetooth logo merges the runes for H (Hagall) and B (Bjarkan) to visually reference Harald’s identity.
Conclusion
Harald Bluetooth Gormsson’s epithet is a testament to the complexity of Viking Age nicknaming practices and the persistent allure of medieval history in popular culture. While many accept that a discolored tooth inspired the nickname, alternative explanations—such as the Gaelic overlap in his father’s name or the possibility of a famously “blue” sword—indicate the ongoing debates and fragmentary nature of medieval sources. Ultimately, the widely accepted viewpoint remains that “Bluetooth” referred to something about Harald personally, most likely a distinctive tooth. Yet, just as his father’s name, Gorm, presents a linguistic curiosity, Harald’s epithet continues to invite scholarly scrutiny and public intrigue alike.
References
Adam of Bremen. (c. 1070). Gesta Hammaburgensis Ecclesiae Pontificum. Various editions.
Kardach, J. (2008). “Tech History: Creating the Bluetooth Name and Logo,” IEEE Global History Network(Anecdotal references).
Roesdahl, E. (1987). The Vikings. Penguin.
Sawyer, B. (2000). Medieval Scandinavia: From Conversion to Reformation, Circa 800–1500. University of Minnesota Press.
Saxo Grammaticus. (12th–13th c.). Gesta Danorum. Various editions.
Viking and Medieval Scandinavia (journal by Brepols Publishers). Various articles on Viking Age history, nomenclature, and culture.