Wimund was a bishop who became a seafaring warlord adventurer in the years after 1147. His story is passed down to us by 12th-century English historian William of Newburgh in his Historia rerum anglicarum, Book I, Chapter 24 entitled "Of bishop Wimund, his life unbecoming a bishop, and how he was deprived of his sight".

William tells us that Wimund was "born in the most obscure spot in England." He was educated at Furness Abbey, founded 1123–1127 by the future Stephen I of England. Wimund may have been a member of the party sent from Furness to found a house at Rushen on the Isle of Man by request of Amlaíb son of Gofraid Cróbh bhan, the King of Mann and the Isles, in 1134.

King Amlaíb granted the monks of Furness the right to elect the Bishop of the Isles, and it appears that Wimund was elected to the see during the time of Thurstan (II), Archbishop of York. Thurstan died in early 1140, so that Wimund became Bishop of the Isles in the period 1134–1140. This was a very rapid rise for a young man of apparently obscure origins.

However, as William of Newburgh tells us later, Wimund in time claimed to be the son of the Mormaer of Moray. William, and some later writers, doubted Wimund's claims. Modern historians have been more inclined to take this claim seriously. Some have proposed that Wimund was a son of Óengus of Moray (died 1130), grandson of King Lulach mac Gille Coemgáin. However, his link with Cumbria has led to the supposition that Wimund was a son (possibly illegitimate) of William fitz Duncan, son of King Donnchad mac Maíl Coluim. William held extensive lands in Cumbria through his mother, Octreda, daughter of Cospatrick of Northumbria, and is believed to have been Mormaer or Earl of Moray between Óengus's death in 1130 and his own death in 1147.