He was a Danish Prince, most likely from the 12th or 13th century. He lived walled up as an anchorite (hermit), in a cell built on to the chancel. There have been various theories as to who Magnus was. The theory that he was the son of King Harold has been discounted.
Inscription: Translated from Latin:
There enters this cell a warrior of Denmark's Royal race: Magnus his name, mark of mighty lineage. Casting off his mightiness, he takes the lamb's mildness, and to gain everlasting life becomes a lowly anchorite.