Cadell ap Rhodri

Cadell ap Rhodri (854–909) was King of Seisyllwg, a minor kingdom in southwestern Wales, from about 872 until his death. The son of Rhodri Mawr, King of Gwynedd, Cadell was in turn the father of Hywel Dda, who eventually came to rule most of Wales and caused Welsh laws to be codified. Cadell is considered the founder of the Welsh royal House of Dinefwr.

Life Cadell was the second son of King Rhodri the Great of Gwynedd and Angharad ferch Meurig, a princess from Seisyllwg. He was named after his great great grandfather Cadell ap Brochwel of Powys, whose daughter Nest was the mother of his paternal grandfather Merfyn Frych. His father was said to have six sons in all but the records are inconclusive on details.

Cadell had four known sons: Hywel Dda, Clydog (d. 920), Morgan and Cadwgan. Cadell and Hywel together also conquered Dyfed in 904905, establishing Hywel as the king in that region, strengthened by Hywel's marriage to Elen, daughter of Llywarch ap Hyfaidd, King of Dyfed (d. c. 904). Cadell left his territorial holdings to his sons Hywel and Clydog on his death in 909. After his brother's death, Hywel ruled the two kingdoms jointly as Deheubarth.