Harald Bluetooth became the first Christian king of Denmark according to the Jelling runestone.
Harald ruled Denmark from around 958 and also controlled Norway for part of his reign. The large runestone he commissioned at Jelling says that Harald won all Denmark and Norway and made the Danes Christian. Its wording presents Harald’s conversion and political achievements as royal accomplishments.
The claim should be understood as a royal statement rather than a complete description of how conversion happened. Christianity had already reached Scandinavia through missionaries, merchants, rulers, and international contacts. Harald’s reign nevertheless marked a major stage in Denmark’s official Christianization. The name Bluetooth later inspired the modern wireless technology brand, whose logo combines runic-style initials representing Harald’s name.