According to the "life" or legend of St Gwinear, he was an Irish prince and pupil of St Patrick who, because of his faith was exiled to Brittany by his father King Clito. There during a stag hunt he experienced conversion and later returned to Ireland to find his father had died, and the people now Christian, wanted to make him King. Spurning the crown, he and his sister Piala and others set sail as a party of 777 missionaries ( probably including St Gothian to be connected with Gwithian and the Irish Virgin Derwe whose chapel stood at Menadarva Merther-derwa a mile away from Gwithian ). Gwinears, party is welcomed, bur Teudar, the local tyrant (and villian in the Cornish miracle play Bewens Merysasek) seeing them land attacks with his army from behind, slaughtering many in Gwinear's party. The chief stronghold of Teudar was at Riviere, and now lies buried under the sands at Hayle Towens . Gwinear and a few companions move on to Roseworthy where he was martyred by Teudar.
The legend goes on to say that Gwinear, disliking some quarrelling women there picks up his severed head, and after washing it in a stream which becomes the Red River (this river still runs red to this day much coloured by remnants of tin) walks on to Herland where he is buried. Many remarkable miracles were attributed to him, including the appearance of springs of water where he places his staff. The legend written by a monk, Anselm about 1300 is one of two which escaped burning at the reformation, and is found at Pluvigner, a town also dedicated to St Gwinear in Brittany.