The name Bluetooth is derived from the cognomen of a 10th century king, Harald Bluetooth King of Denmark and Norway from 935 and 936 respectively, to 940.
He is known for his unification of previously warring tribes from Denmark (including Scania, present-day Sweden, where the Bluetooth technology was invented) and Norway.
Bluetooth likewise was intended to unify different technologies like computers and mobile phones.
The name may have been inspired less by the historical Harald than the loose interpretation of him in The Long Ships by Frans Gunnar Bengtsson, a Swedish best-selling Viking-inspired novel.
The Bluetooth logo merges the Nordic runes analogous to the modern Latin H and B: (Haglaz) and (Berkanan).
The logo is similar to an older logo for Beauknit Textiles, a division of Beauknit Corporation. That logo, using the obvious connection of a reversed K and B for Beauknit, is wider and has rounded corners, but is otherwise the same.
From the Wikipedia