St David's Pembrokeshire United Kingdom

Gruffydd ap Cynan is a descendant of the traditional ruling house of Gwynedd, and had previously made an attempt to claim the kingdom in 1075, but had been defeated by Trahaearn ap Caradog and forced to take refuge in Ireland.

Having gathered a force of Danes and Irishmen to support his claim, Gruffydd launches an invasion in 1081, from Waterford in Ireland.

He lands not in Gwynedd but further south near St. David's (in what will become the Paladin of Pembrokeshire).

At the church of St. David's, he meets with Rhys ap Tewdwr, king of Deheubarth, who had shortly before been driven from power by Caradog ap Gruffydd of Glamorgan and Gwent helped by Meilir ap Rhiwallon of Powys and Gruffydd's old nemesis Trahaearn ap Caradog of Gwynedd.

Gruffydd and Rhys make a pact and set forth to give battle.

The battle of Mynydd Carn takes place about a day's march north of St David's.

In the evening Gruffydd and Rhys came up with the forces led by Trahaearn and Caradog ap Gruffydd, who are reported to have had Norman arbalisters in their army.

According to his biography, Gruffydd ap Cynan, insisted on an immediate attack, overruling Rhys who wished to wait until the following morning.

The result is a complete victory for Gruffydd ap Cynan and Rhys ap Tewdwr, with Trahaearn ap Caradog, Caradog ap Gruffydd and Meilir ap Rhiwallon all being killed.

Gruffydd ap Cynan gains control of Gwynedd, and despite later being captured and imprisoned by the Normans for some years, will escape and reigned until 1137, becoming one of the most successful leaders of Gwynedd.

Rhys ap Tewdwr regains Deheubarth and will reign until 1093.

These two are later to play a prominent part in Welsh resistance to the Normans.

The immediate aftermath of the battle helps the Normans, who take advantage quickly of this internal Welsh struggle which has weakened all the major Welsh kingdoms and killed three of their leaders.

Later this year, William the Conqueror becomes the first Norman King to enter Wales and signals his power by marching straight through modern day South Wales along to St. David's, where he receives homage from Rhys ap Tewdwr, who accepts William's overlordship.

The death of Caradog ap Gruffydd splits his kingdom, leaving it in disarray and helping to ensure Norman dominance of the lowlands of Gwent and Glamorgan, leading to the effective collapse of what had formerly been one of the most powerful Welsh kingdoms.