She was reputedly the daughter of Vortimer and wife of Ynyr Gwent, ruler of the area around Caerwent (Monmouthshire). She was the mother of three children; in the fighting in which Vortigern was killed, described by Nennius, Madrun fled with her infant son, Ceidio, first to Carn Fadryn and then to Cornwall, where she died. Churches are dedicated to her at Tintagel, and Minster (near Boscastle) where she was buried. The whole story is of doubtful authority. Feast: 9 April and 19 October.
Baring-Gould and Fisher, iii. 398–9.