The Battle of Mynydd Carn in 1081 reshaped control of Welsh kingdoms, determining the ruling dynasties of both Gwynedd and Deheubarth.
Key Facts
- Year
- 1081
- Alliance (Side A)
- Gruffudd ap Cynan and Rhys ap Tewdwr
- Alliance (Side B)
- Trahaearn ap Caradog, Caradog ap Gruffydd, Meilir ap Rhiwallon
- Invasion origin
- Waterford, Ireland
- Forces recruited
- Danes and Irishmen
- Primary source
- History of Gruffydd ap Cynan (near-contemporary biography)
Location
Cause → Event → Consequence
Gruffudd ap Cynan had been defeated in a 1075 bid for Gwynedd by Trahaearn ap Caradog and fled to Ireland. Meanwhile, Rhys ap Tewdwr, king of Deheubarth, was ousted by a coalition of Caradog ap Gruffydd of Glamorgan and Gwent, Meilir ap Rhiwallon of Powys, and Trahaearn. Both exiled rulers thus shared common enemies and a mutual interest in reclaiming their thrones.
In 1081 Gruffudd ap Cynan launched an invasion from Waterford with a force of Danes and Irishmen, landing near St David's in south Wales. There he met Rhys ap Tewdwr and the two formed a pact. Together they confronted the coalition of Trahaearn ap Caradog, Caradog ap Gruffydd, and Meilir ap Rhiwallon at the Battle of Mynydd Carn.
The source describes the battle's result as having a radical effect on Welsh history. The victory enabled Gruffudd ap Cynan to establish control over Gwynedd and allowed Rhys ap Tewdwr to reassert rule over Deheubarth, reshaping the dynastic landscape of medieval Wales for a generation.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Gruffudd ap Cynan, Rhys ap Tewdwr.
Side B
1 belligerent
Trahaearn ap Caradog, Caradog ap Gruffydd, Meilir ap Rhiwallon.