Penychen was a possible minor kingdom of
early mediæval Walesand later a cantrefof the Kingdom of Morgannwg. Penychen was one of three cantrefs that made up the kingdom of Glywysing, the other two being Gwynllwgand Gorfynydd. The cantrefi were created on the death of Glywys(c.480 AD), the first king of Glywysing, when the kingdom was divided between three of his sons, Pawl, Gwynllywand Mechwyn. Pawl was the ruler of Penychen [ [http://www.earlybritishkingdoms.com/bios/pawlpgg.html David Nash Ford's Early British Kingdoms] ] and on his death (c.540 AD) passed the cantref onto his nephew.
Pawl's brother Gwynllyw was the ruler of Gwynllwg and upon his death the cantref passed to his son
Cadoc(Cadwg), also known as St. Cadoc. Cadoc would later take control of Penychen, but when he was killed by the Saxons he had no heirs and the both cantrefi fell under the control of Meuregof Gwentand both were absorbed into his kingdom.
Penychen lay between
Senghenyddand Gwrinydd in South Wales["The Welsh Academy Encyclopaedia of Wales". John Davies, Nigel Jenkins, Menna Baines and Peredur Lynch (2008) pg668 ISBN 9780708319536] , it contained the areas which today are the county boroughof Rhondda Cynon Taff, the majority of the Vale of Glamorganand the west of Cardiff.
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