Vita Sancti Carantoci (Life of Saint Carannog/Carantoc(k)). late Eleventh Century AD (c AD 1100):

‘The Life of Saint Carannog (Version One)’ at Academy for Ancient Texts. Ancient Texts Library.
https://www.ancienttexts.org/library/celtic/ctexts/carannog1.html

‘The Life of Saint Carannog (Version Two)’ at Academy for Ancient Texts. Ancient Texts Library.
http://www.ancienttexts.org/library/celtic/ctexts/carannog2.html