Events
Date of Birth: unknown.
Place of Birth: unknown.
Bartrum (Bleddyn ap Cynfyn 26) gives Iorwerth a number of 7 in his generational dating system, implying a birth date of, very roughly, about 1230.
Date of Death: unknown.
Place of Death: unknown.
Relationships
Father: Madog ap Gruffudd ab Owain Brogyntyn.
This relationship is shown by Bartrum (Bleddyn ap Cynfyn 26).
Mother: unknown.
Spouse: Lleucu ferch Llywelyn ap Griffri.
This relationship is shown by Bartrum (Bleddyn ap Cynfyn 26).
Children:
Madog o’r Hendwr married Efa ferch Llywelyn.
References
Bartrum, Peter C., “Bleddyn ap Cynfyn 26” in An Electronic Version of Welsh Genealogies AD 300-1500.
[The sources that Bartrum cites for Iorwerth are: Peniarth 129 (50, 74, 92), copied about 1500 from a 1497 MS by Gutun Owain; and Peniarth 127 (25, 151), written by Syr Thomas ap Ieuan ap Deicws between about 1510 and 1523.]