Nielsen Hayden genealogy
Descendants of Llywarch ap Trahearn
- Aft 1124Father: Trahearn ap Caradog, King of Gwynedd (of Arwystli, Wales - 1081)
Llywarch ap Trahearn ( - Aft 1124)
   └─ Gwladus ferch Llywarch
    Owain Gwynedd, King of Gwynedd ( - 1169 bur.Bangor Cathedral, Bangor, Gwynedd, Wales)
       ├─ Iorwerth Drwyndwn ap Owain Gwynedd ( - Abt 1174)
       │ Margred ferch Madog
       │    └─ Llywelyn Fawr ap Iorwerth (Abt 1173 - 11 Apr 1240 Aberconwy Abbey, Conwy, Wales) =>
       │     + (One of the several mistresses of Llywelyn ap Iorwerth)
       │     + Tangwystl
       │     + Joan of England (Bef 1190 - 30 Mar 1236 bur.Llanvaes, Anglesey, Wales)(m. Bef 23 Mar 1205)
       │     + Eve Fitzwarine ( - Aft 1281)(m. 1239)
       └─ Gwenllian ferch Owain
        Owain Cyfeiliog ap Gruffudd ap Maredudd ap Bleddyn ap Cynfyn (Abt 1130 -
        1197 Monastery of Strata Marcella, Welshpool, Montgomeryshire, Wales)
        1197 Monastery of Strata Marcella, Welshpool, Montgomeryshire, Wales)
           │ + Margaret Corbet
            + David de Malpas