Bluetooth's namesake: the 10th-century Viking king and the runestone in Lund
In central Lund, southern Sweden, near the modern university, the Lund History Museum displays a runestone that is the symbolic naming point for the Bluetooth wireless technology found in billions of devices worldwide. The stone refers to the reign of 10th-century Danish king Harald "Bluetooth" Gormsson, whose name was given to the wireless communications technology by Ericsson engineers in the 1990s.
Harald Bluetooth (c. 910-986) succeeded his father on the Danish throne and during his reign brought a large part of Norway into union with Denmark. In his early years on the throne he converted to Christianity and converted his people. He is remembered in northern European history as a unifier; that role of bringing the fragmented Viking tribes under a single crown carried a symbolic meaning that would lend his name to a modern connectivity technology.
The nickname "Bluetooth" is attributed to a discoloured tooth of the king; in Old Norse it was rendered Blátönn, meaning "blue tooth." Historians say his actual tooth colour is likely to have been a dark, decayed bluish-black, which entered local folklore. Some sources have proposed that the nickname meant "of high standing"; however, the dental hypothesis remains the prevailing view.
In 1996, Ericsson engineer Jim Kardach was working alongside Intel and Nokia on a new short-range wireless communications standard. The standard had no agreed working name. Kardach was at the time reading Frans Bengtsson's historical novel The Long Ships, and the figure of Harald Bluetooth provided the inspiration. He told a meeting: "Bluetooth united the Vikings; our technology will unite phones, computers and headsets."
The name was at first taken as a placeholder. For the official trademark, the marketing team proposed alternatives such as PAN (Personal Area Networking) and RadioWire. But the project was under time pressure, so the Bluetooth name stuck, and the Bluetooth Special Interest Group (SIG) was set up in 1998. The Bluetooth logo is itself an Old Norse runic ligature combining the initials H and B for Harald Bluetooth.
The runestone in Lund is a memorial inscription thought to have been raised in 985 by the king's grandson, Sven Forkbeard II. In Old Norse, the text records that Harald "gathered Denmark into one hand and converted the people to Christianity." The stone was originally located in the Danish town of Jelling; it was brought to Lund's university collection in the 19th century.
In 2018, the museum placed the runestone in a special exhibition area that tells the story of Bluetooth technology's founding. The exhibit includes original handwritten notes from the 1996 Ericsson meeting, a prototype of the first Bluetooth chip (1999), and an interactive map showing the global spread of the technology. Annual visitors to the museum stood at 22,000 in 2017; by 2025 the figure had risen to 178,000.
Professor Bjarne Ravn of the Viking Studies department at Lund University says they have transformed the stone into a symbol of modern connectivity: "This stone is testament to the impulse to unify a thousand years ago. Today, when the phone in our pocket connects to another device by 'Bluetooth,' we are reanimating a metaphor used for a political act in the 10th century." To Ravn, this is a rare example of technology naming: a continuous bridge between past and future.
Like Ip Man's grave, the Lund runestone draws visitors with its symbolism. Visitors to the Lund exhibition hall include engineers, historians and ordinary tourists from around the world. Commentators have described the exhibit as "a successful example of the industry-history hybrid." A 2024 Wired article observed that the Bluetooth brand's cultural origins have "shifted from being a piece of corporate trivia to a global carrier of northern European cultural heritage."
Today, Bluetooth technology is used in more than 5 billion active devices worldwide. According to the Bluetooth SIG's 2025 report, certified annual shipments of the standard exceed 7.4 billion. Automotive, healthcare, IoT and wearables make up most of those shipments. The stone displayed in Lund anchors that fact in a historical story: a Viking king united the tribes a thousand years ago; a thousand years on, our devices speak under the same emblem.