Harald Bluetooth
Harald Bluetooth was king of Denmark, from 958 to 986. The King Harald introduced Christianity to Denmark and consolidated his rule over most of Jutland and Zealand. He became king of Denmark and Norway. Harald Bluetooth was responsible for the unification of Denmark and the conquest of Norway. In short, Harald Bluetooth was able to unify the vikings from Denmark and Norway.
The Bluetooth wireless specification design was named afterHarald bluetooth king in 1997, and the Bluetooth logo consists of a bind-rune for his initials, H (ᚼ) and B (ᛒ). The explanation is that Harald must have had a bad tooth that appeared "blue". The name was chosen due to Swedish telecommunication company Ericsson’s Viking heritage.