Step 1 : Introduction to the question "Which invention was named after a medieval king?"
The name "Bluetooth," which refers to the standard for shortrange wireless connections, is derived from Viking King Harald Gormsson, who is credited with uniting Scandinavia. Like many medieval rulers, he also had a nickname: blátonn in Old Norse. It means Bluetooth. Many scholars believe that King Harald became known as Bluetooth because he had a conspicuous dead tooth that literally looked blue. The now iconic Bluetooth logo is actually a combination of King Bluetooth's initials in Scandinavian. Intel mobile engineer Jim Kardac came up with the name in 1997 after reading a book about Vikings.