monk and possibly martyr. Of Welsh origin and sometimes said to be the nephew of Petroc, he is the patron of St Gluvias (Cornwall). He should probably be identified with Glywys, patron of Coedkernew (Gwent) and with Clivis, whose Glamorgan shrine, Merthir Glivis, is mentioned in the Book of Llan Dav. In some 15th-century wills he is called a martyr. Feast: (in Cornwall) 3 May.
G. H. Doble, The Saints of Cornwall, iii (1964), 15–19; Baring-Gould and Fisher, iii. 131–2.