Late Latin name meaning "great". It was borne by a 7th-century saint who was a missionary in Germany. It became popular in Scandinavia after the time of the 11th-century Norwegian king Magnus I, who was said to have been named after
Charlemagne, or Carolus Magnus in Latin (however there was also a Norse name
Magni). The name was borne by six subsequent kings of Norway as well as three kings of Sweden. It was imported to Scotland and Ireland during the Middle Ages.