Melvin Bragg did a radio programme. The link is above on the BBC Radio 4 Web Site
It's about Owain Glyndwr who proclaimed himself Prince of Wales and who is buried secretly in Herefordshire - the position of his grave is passed on to the next generation on the death bed. It's somewhere over in the Golden Valley that leads to Hay on Wye. They mention how the Mortimer Marcher Lord of Hereford and Mid Wales sided with him and how the Welsh were finally recognised through his decedents the Tudors. How Owain used the historian Geoffrey of Monmouths Books to try to unite others - who refers to the British being the decedents of the people of Troy.
Owain Glyndwr tried basically to unseat the Norman Marcher rulers in Wales and thus the Norman King Henry of England wanting himself the rule Wales & the West Midlands with Mortimer ruling the South East England.
Many thanks to AmeriCymru reader Owen Evans for the above message and heads up.