Nielsen Hayden genealogy
Descendants of (Unknown wife or mistress of Cynfyn ap Gwerystan)
(Unknown wife or mistress of Cynfyn ap Gwerystan)
Cynfyn ap Gwerystan (Abt 1000 - ??)
   └─ Iwerydd ferch Cynfyn
    Edwin of Tegeingl ( - 1073)
       ├─ Owain ab Edwin ( - 1104)
       │ (Unknown daughter of Ednywain Bendew)
       │    │ + Gruffydd ap Cynan ab Iago, King of Gwynedd (Abt 1055 - 1137)(m. Abt 1095)
       │    │ +
       │     + Genilles ferch Hoedlyw ab Ithel an Edryd ab Inethan ab Iasedd ap Carwed ap Marchudd ap Cynan
       └─ Uchdrud ab Edwin ap Gronwy (Abt 1030 - ??)
       
           └─ Maredudd ab Uchtrud ab Edwin ap Gronwy (Abt 1100 - ??) =>
            + Jonet ferch Ithel ab Einudd