In adulthood Cadoc refused to take charge of his father’s army, “preferring to fight for Christ”. He founded his first monastery at Llancarfan in the Vale of Glamorgan, and from there he went to Ireland to study for three years. Returning to Wales, he studied with Bachan, a teacher of rhetoric from Italy. He then travelled to Scotland where he founded a monastery at Cambuslang. Back at Llancarfan, his influence helped it to grow into one of the chief monasteries in South Wales.
His Feast Day is September 25.