Around 1110, the Marcher lord Gilbert de Clare built an early motte-and-bailey castle, about 44 years after the Norman invasion of England. Gruffydd ap Rhys failed to take it in 1116. Twenty years later he returned with help from Owain Gwynedd and his brother, the sons of the king of Gwynedd, and captured and burned the castle. Their sister Gwenllian was Gruffydd's wife, and the Norman force based at the castle had killed her. Her death brought the support of a powerful Welsh ruling family into the attack on the fortress.
Chapter · 2:36-5:36
The early castle and Gwenllian's family alliance
Gruffydd ap Rhys's failed siege in 1116 was followed twenty years later by a successful attack with help from his wife's family in Gwynedd.