Nielsen Hayden genealogy
Descendants of Cadwgon ap Madog ap Cadwgon ap Bleddyn
Mother: Jane ferch Cynwrig
Cadwgon ap Madog ap Cadwgon ap Bleddyn
   └─ Madog ap Cadwgon ap Madog ap Cadwgon (Abt 1170 of Nannau, Meirionnydd, Wales - ??)
    Efa ferch Madog ap Philip ab Uchtrud
       └─ Nest ferch Madog
        Einion ap Seisyll (Abt 1170 - ??)
            + Thomas ap Rhodri ab Owain Gwynned (Abt 1170 - ??)