Much like Harald Fairhair, Harald Bluetooth (also known as Harald Gormson) set up to unify Denmark under a single ruler in which he succeeded in 958CE, ruling until 985CE. He also brought Christianity to Denmark. He was known as Bluetooth because of a root problem with one of his teeth which was slightly darker than the other teeth in his mouth. Harald Bluetooth was also King of Norway in the 970s. 1000 years later, Ericsson researchers with the basis of technology that originally created in the 1940s by Austrian born - American actress Hedy Lamarr created Bluetooth technology (naming it after Harald) which we use today for things like wireless headphones and speakers. The logo for Bluetooth is a combination of his initials in the runes of the Roman alphabet.