Bluetooth Is Named After a 10th-Century Viking King Who Ate Too Many Blueberries

The next time you pair wireless headphones, you are invoking the name of a 10th-century Viking king.

Bluetooth, the short-range wireless standard that now ships on more than 5 billion devices annually, is named after Harald 'Bluetooth' Gormsson, King of Denmark from approximately 958 to 986 AD and King of Norway from roughly 970 to 986. The wireless technology that unites your phone, headphones, keyboard, car, and smartwatch is named after a man who died 1,040 years ago.

THE KING BEHIND THE NAME

Harald Gormsson was the son of Gorm the Old and Thyra, the first monarchs of a recognizably unified Denmark. The runestones Harald erected at Jelling, still standing in central Denmark today, declare that he 'won for himself all of Denmark and Norway, and made the Danes Christian.' Scholars at the National Museum of Denmark consider the Jelling stones the closest thing to Denmark's birth certificate.

His nickname, 'Blåtand' in Old Norse, is recorded in the 12th-century Roskilde Chronicle. The nickname's origin is disputed. One theory holds that he had a prominent dead tooth that had darkened with decay, appearing blue-black. Another claims he loved blueberries so thoroughly that his teeth were permanently stained. Medieval sources are not reliable on dental hygiene. What is certain is that the nickname stuck.

Harald's political accomplishment, however, was real and uncontested. He unified the warring Danish tribes under a single crown, extended his authority over Norway, built defensive ring fortresses (the Trelleborgs) across his kingdom, and converted Denmark to Christianity. He was, in the language of modern project management, the lead engineer of medieval Scandinavian interoperability.

HOW A NAMING MEETING IN 1996 PICKED HIM

Fast forward to 1996. Intel, Nokia, and Ericsson were collaborating on a short-range wireless protocol for cable replacement — a way to let a mobile phone talk to a headset, a laptop talk to a printer, without running wires. The engineering was mature. The name was not.

Jim Kardach, an Intel mobile computing engineer, later recounted the story in a 2008 EE Times essay. He had just read 'The Long Ships' by Frans G. Bengtsson, a 1941 historical novel about Viking raiders, and was struck by the figure of Harald Bluetooth. In a naming meeting with his Ericsson counterpart Sven Mattisson, Kardach proposed 'Bluetooth' as a temporary code name. The metaphor was tidy: Harald unified Scandinavia; the protocol would unify wireless devices from different manufacturers.

The original plan was to use 'Bluetooth' only during development and replace it with a polished marketing name — candidates included 'PAN' (Personal Area Network) and 'RadioWire' — before public launch. Legal conflicts around 'PAN' as a trademark delayed that rebranding. By the time the Bluetooth Special Interest Group formally launched in May 1998, the code name had leaked into press coverage and product datasheets. Rebranding would have meant starting the marketing push over. They kept it.

THE RUNIC LOGO

The Bluetooth logo is also Harald. It is a bind rune — a combination of two runes from the Younger Futhark alphabet used in 10th-century Scandinavia. The logo merges ᚼ (Hagall, equivalent to the Latin letter H) and ᛒ (Bjarkan, equivalent to B). These are Harald Bluetooth's initials in runic script, stylized and overlaid.

Most users who tap the icon in their phone's settings have no idea they are looking at the carved initials of a Viking king. Kardach reportedly wanted it that way. The logo is a Trojan horse of medieval history, smuggled into every smartphone in the world.

WHY IT MATTERS

Bluetooth is one of the most successful wireless standards in history. According to the Bluetooth Special Interest Group's 2024 market update, roughly 5.4 billion Bluetooth-enabled products will ship in 2026, and the installed base globally exceeds 20 billion devices. It carries audio for AirPods, telemetry for medical implants, connectivity for car infotainment, and control signals for nearly every IoT device in the consumer market.

That an Intel engineer reading a Viking novel in 1996 picked a 10th-century king's nickname, failed to replace it with a sanitized brand name in time, and ended up stamping that king's runic initials on every Bluetooth-enabled device built since — is one of the stranger through-lines in commercial technology. Names matter. Once the metaphor took hold, rebranding became impossible.

Harald Bluetooth spent his life building interoperability between rival Scandinavian tribes. A thousand years later, his name is carved into every phone that talks to every headset in the world. The metaphor turned out to be exactly accurate.

(Sources: Bluetooth SIG, 'How Bluetooth Got Its Name'; Jim Kardach, 'Tech History: How Bluetooth Got Its Name,' EE Times, March 2008; National Museum of Denmark, Jelling Stones exhibit; Saxo Grammaticus, Gesta Danorum; Roskilde Chronicle; Bluetooth Market Update 2024, Bluetooth SIG)