As we may know, Bluetooth is a wireless technology standard for exchanging data over short distances. It was developed by Ericsson mobile, initiated in 1989 by CTO Nils Rydbeck and Swedish medical doctor, scientist, and inventor Johan Ullman.
But do you know the origin of the name and logo?
Origin of the name “Bluetooth”
The idea for the name “bluetooth” was proposed by Jim Kardach of Intel in 1997. He developed a system that would allow mobile phones to communicate with computers. It is an Anglicised version of the Scandinavian Blåtand/Blåtann (Old Norse blát?nn), the epithet of the tenth-century king Harald Bluetooth who united dissonant Danish tribes into a single kingdom and, according to legend, introduced Christianity as well.
According to Jim Kardach, “When asked about the name Bluetooth, I explained that Bluetooth was borrowed from the 10th century, second King of Denmark, King Harald Bluetooth; who was famous for uniting Scandinavia just as we intended to unite the PC and cellular industries with a short-range wireless link.”
At that time, Jim was reading Frans G. Bengtsson’s historical novel The Long Ships about Vikings and King Harald Bluetooth.
“When I got home from this business trip, a history book I had ordered called the The Vikings by Gwyn Jones” had arrived. Thumbing through the book, I found this (see Figure 2) picture of a giant rock, or runic stone, which depicted the chivalry of Harald Bluetooth, the guy which Sven just told me about! ”
The implication is that Bluetooth does the same with communications protocols, uniting them into one universal standard.
Origin of the “Bluetooth” logo
The Bluetooth logo is the combination of “H” and “B,” the initials of Harald Bluetooth, written in the ancient letters used by Vikings, which are called “runes.”
It is a bind rune merging the Younger Futhark runes 
(Hagall) (?) and 
(Bjarkan) (?), Harald’s initials. (A bind rune (Icelandic: bandrún) is a ligature of two or more runes. They are extremely rare in Viking Age inscriptions, but are common in earlier (Proto-Norse) and later (medieval) inscriptions. On some runestones, bind runes may have been ornamental and used to highlight the name of the carver.)
