Patron and founder of Llangollen church (Clwyd) and of Colan (Cornwall), and perhaps of Langolen in Finistère (Brittany). Nothing is known of this saint, but a Life in Welsh survives in two MSS. of the 16th century. This farrago makes Collen fight a duel with a pagan Saracen in the presence of the pope, go to Cornwall and Glastonbury, and deliver the people in the Vale of Llangollen from a fierce giantess by slaying her. Feast: 21 May.
Baring-Gould and Fisher, ii. 157–61.