Harald "Bluetooth" Gormsson (c.935-986) was the son of the first historically recognized King of Denmark. Harald created the largest of the Jelling Stones (his father had set up the first). These commemorative stones carry inscriptions that include the earliest reference to Denmark as a nation. He also conducted important building projects, including a half-dozen massive stone ring forts and the oldest known bridge in southern Scandinavia, the half-mile long stone Ravninge Bridge (no longer extant).
He seemed to prefer negotiating over fighting, and managed to join and keep Danish tribes together, and briefly ruled Norway (okay, that was by force, after their king was assassinated). Perhaps it was his less-aggressive nature that made him amenable to Christianity, although the stories of his conversion are varied. One says he converted on a dare, when a monk named Poppa "proved" the power of God by carrying a heavy brand from the fire without being harmed. One story says he was converted against his will when he had been defeated by Otto I (founder of the Holy Roman Empire). Another account (written centuries after Harald's death) says it was Otto II who forced him to convert. Whatever the case, Harald converted in the 960s, and took it seriously: he transferred his father's body from a pagan-style grave in an ancient mound to a church.
|This commemorates Harald's conversion.|
Whatever! What we can document is that one of the developers of the Bluetooth technology was reading a historical novel about Harald on the side. He felt that his protocol would unite different devices in a way analogous to Harald uniting different tribes in Denmark, instead of having them conflict with each other. He proposed calling the protocol Blåtand, Harald's nickname in Scandinavian. Although early Ericsson documents use this name, it formally became the English word "Bluetooth™"; I have read that folk in Scandinavian countries frequently use Blåtand instead of the official English name.