Rhys ap Hywel was born in about 1200, in Glasbury, Breconshire, Wales, probably in Aberllynf. He was the son of Hywel ap Trahaearn ap Gwgon ap Bleddyn ap Maenyrch and his wife Gwenllian ferch Rhys ap Bledri Latimer ap Cydifor Fawr, and of the tribe of Bleddyn ap Maenyrch.
He married Catrin ferch Gruffudd "Gŵyr". The children listed by Bartrum are:
Einion "Sais" ap Rhys, b. Abt 1230, of, Pen-pont, Llansbyddyd, Breconshire, Wales, d. Aft 1271 (Age ~ 42 years); m1. Unknown; m2. Lleucu ferch Hywel; m3. Gwenllian ferch Hywel
Dafydd ap Rhys, b. Abt 1230, of, Aberllynfi, Breconshire, Wales; m1. Gwenllian ferch Hywel "Felyn"; m2. Catrin ferch Hywel
Hywel "Morgannwg" ap Rhys, b. Abt 1230, of, Aberllynfi, Breconshire, Wales
Gruffudd ap Rhys, b. Abt 1270, of, Aberllynfi, Breconshire, Wales; m. had issue
possibly Caradog (pencilled in on Bartrum charts)
FamilySearch AFN: 49TM-64S, citing the following sources: BIRTH-MARRIAGE:"A HISTORY OF THE COUNTY OF BRECKNOCK", by Theophilus Jones, pub. in London, England, in 1805. LDS FHC microfilm #0990114, p. 249. BIRTH:"WELSH GENEALOGIES AD300-1400," by Peter Clement Bartrum, published by The University of Wales Press, 1980. BIRTH-MARRIAGE:HARLEY 2289, microfilm from The British Library, London, England.
Carl Boyer, 3rd. Medieval Welsh Ancestors of Certain Americans. Santa Clarita, CA: n.p., 2004. [ ] , page 40