Yspwys Mwyntyrch, King of Calchfynedd
(Born. c.AD 530 or 430)
(Latin: Isbuius; English: Ospewis)

Yspwys is a perplexing character. He was supposedly the son of another King Yspwys, eldest son & successor of King Cadrod Calchfynedd. Solid dating of his near descendants, Maeldaf Hynaf and SS. Tagfan & Elian Geimiad shows, however, that he actually flourished around a hundred years prior to his traditional grandfather. Tradition follows suite, making Yspwys a contemporary and ally of High-King Ambrosius Aurelianus while he was exiled in Brittany (or Spain, as this particular story has it). He was rewarded with lands in Meirionydd though, not Middle Britain. It is likely that two people of the same name have become confused.

It was probably during the reign of the later Yspwys that the British armies of Calchfynedd were defeated by King Cuthwulf of Wessex, in AD 571, at the Battle of Bedford. However, the West Saxons did not settle very deep into this British territory for some generations and the Calchfynedd dynasty probably survived for a time. Yspwys was succeeded by his son, Mynan.