Dictionary of National Biography, 1885-1900/Madog ap Gruffydd Maelor
MADOG ap GRUFFYDD MAELOR (d. 1236), prince of Northern Powys, probably succeeded on the death of his father, Gruffydd Maelor, in 1191, to the greater part of that principality, and in 1197, by the death of his brother Owain, became ruler of the whole. It was in the latter year that Gwenwynwyn [q. v.] inherited from his father, Owain Cyfeiliog, the southern half of Powys, so that the two regions, remaining for some twenty years in the hands of these two princes, came naturally to be known as Powys Fadog and Powys Wenwynwyn. Madog was a contemporary of Llywelyn ab Iorwerth [q. v.], and is at all times found acting with the minor princes whom that great ruler controlled and occasionally drove into rebellion. He joined Llywelyn, Gwenwynwyn, and the South Welsh princes in writing to complain to Innocent III of the ecclesiastical tyranny exercised by England over Wales (Giraldus Cambrensis, De Jure et Statu Menevensis Ecclesiæ, Dist. iv.) In 1211, when John invaded Wales in order to humble Llywelyn, Madog was one of the band of princes who seized the opportunity to cast off the yoke of Gwynedd. Like the rest, he returned in 1212 to his old allegiance. His name appears in a list of Llywelyn's allies drawn up on 18 Aug. 1214 (Bridgeman, Princes of Upper Powys, document 9), and his household troops were with the Prince of Gwynedd in the South Welsh expedition of December 1215. In 1223 he was one of the princes who undertook, in case Llywelyn did not observe his promises to the king, to make good the default (Rymer, Fœdera, ed. 1739, tom. i. pt. i. p. 89). He died in 1236.
Madog was the founder of Valle Crucis (or Llan Egwestl) Abbey, the building of which began in 1200. The ‘Myvyrian Archaiology’ contains one poem in his honour by Llywarch ab Llywelyn (2nd edit. p. 209) and two by Einion Wan (pp. 232–3).
[Annales Cambriæ, Rolls edit.; Brut y Tywysogion, Oxford edit. of the Red Book of Hergest, vol. ii.; poems in the Myvyrian Archaiology.]