Gruffudd pushed into Saxon England, burning the city of Hereford, overwhelming border patrols, and proving the English defences there entirely inadequate to respond to Welsh invasions.
[3] In the wake of this campaign, Gruffudd was turned upon by his own men, who killed him in 1063 and shipped his head off to Edward the Confessor in exchange for the redivision of Wales into its traditional kingdoms.
[4] This left a vacuum of power in Wales in which princes and kings were free to squabble over their lands, without the unifying presence of Gruffudd to ward off Norman attacks.
This served as a base from which the Normans continued to expand westward into Wales, establishing a castle at Caerleon by 1086 and extinguishing the Welsh Kingdom of Gwent.
[8] However, the attacks in south-east Wales "faltered badly when [the earl of Hereford’s] son [Roger de Breteuil]... forfeited his estates for treason in 1075 and involved some of his vassals on the Welsh frontier in his downfall".
Throughout the period, Henry exerted a great deal of control over Wales, establishing a series of new castles and placing new Lords into positions of power.
He experienced costly ambushes and therefore defeat, particularly in the Battle of Ewloe at Coleshill / Coed Eulo, where Henry was almost killed in the fighting, but managed to return to friendly lines.
He moved against his Adversaries again in 1163, and, with Welsh resistance exhausted, gained homage from the two most powerful princes of Wales, Rhys ap Gruffydd and Owain Gwynedd, along with the king of Scotland.