King of Morgannwg (1074-1081)
Caradog ap Gruffudd was the son of Gruffudd ap Rhydderch who had sought to establish himself as king in Deheubarth and met his death at the hands of Gruffudd ap Llywelyn in 1055. After the death of Gruffudd ap Llywelyn himself in 1063 he seems to have managed to establish himself as ruler in Gwynllwg and parts of Gwent, detaching those areas from the authority of the kings of Morgannwg.
Like his father he was a ruthless adventurer, eager to take any opportunity to expand his authority and dominion, emerging as one of the key figures in eleventh century Wales. He felt no compunction in challenging the authority of the king of England as in 1065 he launched a successful raid against a hunting lodge established by Harold Godwinson at Portskewet in Gwent.
His activities attracted the attention of the reigning king of Deheubarth, Maredudd ab Owain ab Edwin, who must have perceived Caradog as a threat to his domination of the south, and in 1072 Maredudd moved against him, and attempted to invade Gwynllwg. They met in battle on the banks of the Rhymni; Caradog with the assistance of Norman troops defeated and killed his rival. Emboldened by this victory, in 1074 he succeeded in driving the reigning king of Morgannwg, Cadwgan ap Meurig from his kingdom and added the remainder of Morgannwg to his dominions.
His aim then seems to have been to extend his control westwards over Deheubarth as well. To this end, established an alliance or at least an understanding with his counterparts in Gwynedd, that is Bleddyn ap Cynfyn and his successor Trehaern ap Caradog.
In 1078 he succeeded in killing the king of Deheubarth, Rhys ab Owain but
could not attract enough support to establish himself in Deheubarth
and Rhys ap Tewdwr became the new king. This did not however dissuade Caradog from trying again and in 1081, with the support of Trehaern ap Caradog they launched a combined invasion of Deheubarth seeking to put and end to the rule of Rhys ap Tewdwr.
The two opposing forces met at the Battle of Mynydd Carn and unfortunately for Caradog it was Rhys ap Tewdwr and his ally Gruffudd ap Cynan who emerged victorious. Caradog died on the battlefield bringing his tempestuous reign to an end. He was effectively the last ruler in south east Wales of any authority and stature. After his death the figure of Iestyn ap Gwrgan took over in Morgannwg but the Normans rapidly moved in on Gwent and the old hegemony of the south east was broken.
Sourced from Brut y Tywysogion, and The Welsh Kings by Kari Maund (Tempus 2000)