It was first developed by Sven Mattison and Jaap Haartsen who were working for Ericsson Mobile platforms. Bluetooth is formally known as IEEE 802.15.1.
The name Bluetooth is derived from a Danish Viking and King Harald Blatand (translated as Bluetooth in English) who lived in the latter part of the 10th century. He united and controlled Denmark and Norway. He got his name from his very dark hair which was uncommon for Vikings. Blatand means dark complexion. However a more popular reason is that he had a strong inclination for eating blueberries which made his teeth stained with the color. Its logo merges with the Nordic runes analogous to the modern Latin H and B.