The popularity of the name "Magnus" in Shetland over the centuries is no doubt due to him.
He was the son of Erlend Thorfinnsson, Earl of Orkney.
Earl of Orkney from c. 1108-c. 1115, St Magnus was a Norseman, but not really a Viking. This is proven by the fact that he refused to engage in a violent raid on Anglesey in Wales. Because of this, he had to take refuge in Scotland.
He was martyred around Eastertime, on the Isle of Egilsay in Orkney.
His shrine is in Kirkwall. The unfinished cathedral at Kirkjubøur in the Faroe Islands is dedicated to him.
There are a number of other saints with the same name, which he should not be confused with, notably:
- Magnus of Anagni
- Magnus of Cuneo
- Magnus of Füssen
- Magnus of Avignon
- Magnus of Oderzo
None of these appear to have dedications in Shetland.