If you look closely at the Bluetooth icon on your phone, you’ll see a little angular glyph, two triangular blades meeting at a vertical line. That shape has a quite specific meaning. It’s built from the initials of a Viking king who died more than a thousand years ago, written with runes used in Scandinavia during his lifetime.
The wireless standard connecting your earbuds to your phone is named after a man who lived a millennium before radio. The reason why is one of the better accidents in tech naming history, and it happened because a conversation about a Viking novel on a business trip sent an Intel engineer down exactly the right historical rabbit hole.
The king probably had a bad tooth and a big ambition
Harald Blåtand built a kingdom and changed its religion
Harald Gormsson ruled Denmark from roughly 958 until the late 980s, the son of King Gorm the Old and Queen Thyra. He’s remembered for consolidating Danish rule, extending his power into Norway, and presiding over Denmark’s conversion to Christianity. His own monument at Jelling makes the claim rather boldly, declaring that Harald “won for himself all Denmark and Norway” and “made the Danes Christians.”
That inscription appears on the larger of two surviving runestones at Jelling, near Harald’s royal seat. The smaller stone was erected by his father, Gorm, in memory of Thyra. Harald’s larger stone commemorated his parents while also advertising his own achievements, and today the Jelling complex is a UNESCO World Heritage site closely associated with the formation and Christianization of Denmark.
The Bluetooth nickname is murkier. The earliest surviving record of Blåtand appears in the 12th-century Roskilde Chronicle, well after Harald’s death. The traditional explanation is that he had a conspicuous tooth that appeared dark, blue-grey, or nearly black, although nobody can verify the condition of a tenth-century king’s teeth with much confidence.
So, a possibly thousand-year-old dental problem is, improbably, part of the reason your headphones connect under the name Bluetooth.
An Intel engineer found him on a business trip
A Danish colleague, two Viking books, and a codename that refused to die
By the mid-1990s, Ericsson, Intel, and Nokia were working on separate short-range radio projects and trying to establish a common technology that could connect the PC and cellular industries. Intel engineer Jim Kardach realized the collaboration needed a shared codename while the companies worked out what the finished technology would eventually be called.
The name began to take shape after a meeting in Toronto. Over drinks, Ericsson engineer Sven Mattisson told Kardach about Frans G. Bengtsson’s Viking novel The Long Ships, whose story included Harald Bluetooth. When Kardach returned home, a history book he’d ordered, Gwyn Jones’s The Vikings, was waiting for him. Inside, he encountered Harald again, this time alongside an image of the famous Jelling stone and its inscription about the king’s achievements.
Kardach saw an obvious parallel between a king remembered for uniting territories and a project aimed at uniting the PC and cellular industries. He proposed “Bluetooth” as a codename and digitized the image of the Jelling stone for a presentation. He thought its human figure depicted Harald, then added a notebook computer to one hand and a cellphone to the other.
There was only one problem: the figure wasn’t Harald. Kardach later discovered that he’d put a laptop and a phone into Christ’s hands. The figure on that face of the Jelling stone is an early Scandinavian depiction of Jesus, complete with marks Kardach eventually noticed on the palms. He and his colleagues quietly stopped using the doctored image.
Bluetooth was still only a codename at this point. When the group went looking for a proper commercial name, the leading candidates were PAN, short for Personal Area Networking, and RadioWire. PAN was the favorite, but searches turned up the term everywhere, creating obvious problems for a distinctive brand. A full trademark search for RadioWire couldn’t be completed before launch. With PAN effectively unusable and RadioWire still awaiting clearance, the temporary Bluetooth name remained.
By May 1998, Ericsson, IBM, Intel, Nokia, and Toshiba had formed the Bluetooth Special Interest Group around the technology. By then, the codename had been in use long enough that changing it made little sense.
The logo is literally his initials
Two runes turned a Viking nickname into an icon
Once the name stuck, the logo followed the same historical idea. It’s a bind rune, a single symbol formed by merging two Younger Futhark runes, Hagall (ᚼ) for H and Bjarkan (ᛒ) for B. If you put them together, you get H and B, the initials of Harald Blåtand, arranged into the symbol now sitting on phones, laptops, cars, headphones, speakers, and just about everything else with Bluetooth.
Younger Futhark was the common 16-character runic alphabet of Viking Age Scandinavia, precisely the period in which Harald lived. Hagall and Bjarkan therefore come from the same runic tradition used during his lifetime. Runic writing continued to evolve after the Viking Age, but the logo’s basic historical reference is genuine.
In other words, one of the world’s most familiar wireless symbols is Harald Blåtand’s monogram in Viking Age runes.
Two failed names left a Viking king in your quick settings
PAN’s branding problems and RadioWire’s unfinished trademark search gave the temporary Bluetooth codename enough time to stick. What started as Kardach’s reference to a Viking king eventually became one of the most recognizable names in consumer technology, surviving successive generations of Bluetooth without losing either its name or its rune-inspired logo.
Modern Bluetooth is doing considerably more for that little icon than the original engineers envisioned. On phones, Bluetooth can also broadcast in the background for certain discovery features, while connections can rely on Bluetooth encryption to protect data moving between devices.
So the next time your phone finds a speaker across the room, look at the icon beside the connection for a second. Those sharp little lines are H and B fused together in Viking Age runes, carrying Harald Blåtand’s initials from tenth-century Denmark all the way into your phone’s quick settings.