Byordderch was born in 0590.1 Byordderch's father was Gwylawr ap Gwynfyw and his mother was <Unknown>. His paternal grandparents were Gwynfyw ap Cadell and <Unknown>. He was an only child.
General Notes
Sources:
1. Author: Peter C., Bartrum Title: Welsh Genealogies AD 300-1400 Publication: Name: University of Wales Press; Date: , 1978; Repository: Name: Celtic Royal Genealogy database by Arthur E. Turner-Thomas