Why did they name bluetooth after harald bluetooth?

Answer 1

Harald I of Denmark who had the nickname Blåtand, meaning blue-tooth (but it could also mean black-tooth, which to me sounds a lot more likely) was responsible for merging the different tribes of Denmark into a single kingdom. The Bluetooth standard was created to replace RS-232 (serial) cables, a widely used standard, and it was imagined that this would create a single unifying standard for ultra-short-range data transmission at a time when other standards such as wi-fi and wireless USB were also being developed. It was only partly successful in this, as the different wireless systems each have their own advantages and appropriate applications.

Answer 2

His teeth weren't blue. Blåtand in old Viking describes a person with very dark hair and dark complexion. He was a "people's person - a great enabler and facilitator. He made people talk to each other. He brought Christianity to Scandinavia. He united Denmark and Norway.