Cadrod Calchfynedd, King of Calchfynedd
(Born. c.AD 510)
(Latin: Catrotius; English: Cadred)

Cadrod was one of the 'Gwyr y Gogledd' or Men of the North. However, his Kingdom of Calchfynedd is one of the most mysterious of Early British Kingdoms. The name, literally, means Chalk Mountains or, more generally, Limestone Hills. W.F. Skene argued, not unconvincingly, that this referred to the Kelso area of Southern Scotland. Yet ancient Welsh poetry clearly indicates that it was south of Powys. Late descriptions of Cadrod as 'Earl of Dunstable' and 'Lord of Northampton' show that medieval writers thought that he lived in the Chilterns. Calchfynedd may well, therefore, have been the kingdom later taken over by the Anglo-Saxons and known as Chilternset.

Cadrod was the son of Cynwyd Cynwydion, a prince of Ebrauc (York) who was probably ejected from whatever part of that kingdom he had inherited. His people may have moved south to where Cadrod, as their eventual monarch, established their new kingdom. The power of any previous British leaders in the Chilterns may already have been broken, while the Anglo-Saxon had not yet moved into the area. Cadrod married Gwrygon Goddeu, one of the many daughters of King Brychan Brycheioniog. They became the parents of King Yspwys, grandparents of Yspwys Mwyntyrch and direct male line ancestors of the Royal Tudor Dynasty.

Records of Cadrod Calchfynedd date back to the 11th century. It is possible that he is historic.