Dictionary of National Biography, 1885-1900/Owain ap Cadwgan
OWAIN ap CADWGAN (d. 1116), prince of Powys, was the son of Cadwgan ap Bleddyn ap Cynfyn [see Cadwgan, d. 1112]. He spent a part of his childhood at the court of Muircheartach, king of Dublin and of Munster, whither he was sent for protection during the ‘invasion of the two earls’ (1098), but he no doubt returned to Wales when his father became lord of Ceredigion and part of Powys. In 1106 he murdered Meurig and Griffri, sons of Trahaiarn ap Caradog, a deed which early betrayed the violence of his disposition. In 1110 he committed an outrage which had serious consequences. Gerald of Windsor, the castellan of Pembroke, was building himself a home at Cenarth Bychan (unidentified, but possibly Carew; Laws, Little England beyond Wales, p. 105), and had already taken thither his wife Nest (daughter of Rhys ap Tewdwr) and her children. Owain paid a visit to Nest, who was his second cousin, and, becoming violently enamoured of her, organised a night attack upon the half-built fortress and carried her off. Cadwgan vainly endeavoured to ward off the vengeance certain to follow such a deed by inducing Owain to restore his captive. Other Welsh princes were sent into Cadwgan's territories by Henry I to avenge the wrongs of his officer, and father and son were forced to go into hiding. Owain sailed across to Ireland and so sought refuge with his old protector, Muircheartach. Cadwgan was able in a little while to recover Ceredigion, but had to promise that he would have no dealings with his lawless son. Unfortunatunely, he had no control over Owain's movements. Before the end of the year the fugative had returned, and, finding the new prince of Powys, Madog ap Rhiryd, at odds with the Normans, entered into an alliance with him, Henry set another ruler over Powys in the person of Iorwerth ap Bleddyn [q. v.], whereupon Owain and Madog established themselves as freebooters, using Iorwerth's territory as a retreat. It was in vain that Iorwerth appealed to them to have some regard for his reputation ; they only quitted his territory when he gathered together a host against them. After devastating Meirionydd, Owain ventured once again into Ceredigion, and soon begun a course of border plunder at the expense of the men of Dyfed. The murder of a prominent Fleming, William of Brabant, by Owain and his men was reported to Henry as he was in conference with Cadwgan. Convinced that nothing could he made of Owain, the king now deprived Cadwgan of Ceredigion, which was given to Gilbert de Clare. Owain thereupon made his escape once more to Ireland. But in 1112 Iorwerth of Powys wos slain by Madog ap Rhiryd, the vacant lordship was given to Cadwgan, and Owain was forgiven. Madog, however, slew Cadwgan before Owain reappeared in Powys; he received a portion of the lordship from the crown authorities, but the greater part was given to Owain. In the following year Madog fell into the hands of Owain's captain of the guards, Maredudd ap Bleddyn [q. v.], and at Owain's command the captive was blinded and deprived of his lands.
Henry I's expedition of 1114 was largely directed against Owuin, who took refuge with Grunydd ap Cynan ; but the Welsh had not much difficulty in purchasing terms of peace, and when Henry crossed to Normandy in September, the prince of Powys was one of his retinue. He returned with the king in the following July, having in the meantime been knighted. So completely was he now restored to favour that in 1116 Henry entrusted to him the task of subduing the rebellious Oruffydd ap Rthys [q. v.], who was actively asserting his claim to the lordship of Deheubarth. Owain led a host into Ystrad Tywi, but, while ravaging with a small company near Carmarthen, was unexpectedly attacked by a Flemish army under Gerald of Windsor and killed.
Annuales Cambriæ; Bret y Tyeymogion, Oxfprd edit. pp. 280-302; Flor. Wig.]