They captured five castles in the north of Ceredigion then later in the year launched a second invasion, inflicting a heavy defeat on the Normans at the Battle of Crug Mawr, just outside Cardigan.
Cadwaladr joined with Ranulph, Earl of Chester in the attack on Lincoln in 1141,[2] when King Stephen of England was taken prisoner.
Cadwaladr apparently abandoned or escaped from his allies and made peace with his brother, who obliged the Dubliners to leave.
In 1147 Hywel ab Owain Gwynedd and his brother Cynan drove Cadwaladr from his remaining lands in Meirionnydd.
A further quarrel with his brother Owain led to Cadwaladr being driven into exile in England, where King Henry II later gave him lands at Ness in Shropshire.