King Harald Bluetooth lived in Denmark between 910-940 AD, and was the son of Gorm. 

Contrary to popular opinion, Bluetooth or "Blåtand" as it was in old Viking language had nothing to do with a blue tooth. 

It means dark complexion – he had very dark hair, which was unusual for Vikings. Not only did Harald not fit the classic image physically, he was a rather unusual Viking. 

That is, if your understanding was that the life of a Viking was all battles and pillage. The good King Harald brought Christianity to Scandinavia and also "united" Denmark and Norway. And while we are destroying long-held beliefs, Vikings did not have horns on their helmets! 

Much of Harald’s history was learnt from two runic stones erected to his memory in the town of Jelling in Denmark. The first concept of the technology that became Bluetooth was created in Lund in Sweden 1994, and Ericsson has now chosen to erect a modern runic stone to the memory of Harald Bluetooth. 

This was unveiled by Ericsson CEO Sven-Christer Nilsson during his recent visit to the Ericsson R&D facilities in Lund. The modern runic stone bears the following inscription (in runic language translated from Swedish): Ericsson Mobile Communications AB erected this stone to the memory of Harald Bluetooth who gave his name to a new wireless technology for mobile communication. 

Ericsson’s R&D facility at Lund is undoubtedly a centre of creative excellence. Bluetooth’s genesis there follows many other new ideas, including the Ericsson mobile phone. In fact, the first portable NMT and GSM phones on the market were developed there. It seems that Ericsson is not only making history, but celebrating it, too.