Nielsen Hayden genealogy
Gwion Sais ap Heilin ap Llywarch ap Gwyn
Abt 1170 -
Generation: 1
Generation: 2
Generation: 3
Generation: 4
1. Gwion Sais ap Heilin ap Llywarch ap Gwyn was born about 1170. Family/Spouse: Unknown. [Group Sheet] [Family Chart]
Children:
Generation: 2
2. (Unknown daughter of Gwion Sais) 
(1.Gwion1)Family/Spouse: Owain ap Gruffudd ab Yr Arglwydd Rhys. Owain (son of Gruffudd ab Yr Arglwydd Rhys and Matilda de Briouze) died on 18 Jan 1236 in Strata Florida Abbey, Ceredigion, Wales; was buried in Strata Florida Abbey, Ceredigion, Wales. [Group Sheet] [Family Chart]
Children:
- 3. Maredudd ab Owain ap Gruffudd ab Yr Arglwydd Rhys died in Mar 1265 in Llanbardarn Fawr, Ceredigion, Wales; was buried in Strata Florida Abbey, Ceredigion, Wales.
- 3. Maredudd ab Owain ap Gruffudd ab Yr Arglwydd Rhys
Generation: 3
3. Maredudd ab Owain ap Gruffudd ab Yr Arglwydd Rhys (2.(Unknown2, 1.Gwion1) died in Mar 1265 in Llanbardarn Fawr, Ceredigion, Wales; was buried in Strata Florida Abbey, Ceredigion, Wales. Family/Spouse: (Unknown daughter of Thomas ap Rhodri). [Group Sheet] [Family Chart]
Children:
- 4. Owain ap Maredudd ab Owain ap Gruffudd was born in of Iscoed, Ceredigion, Wales; died on 15 Aug 1275; was buried in Strata Florida Abbey, Ceredigion, Wales.
- 4. Owain ap Maredudd ab Owain ap Gruffudd
Generation: 4
4. Owain ap Maredudd ab Owain ap Gruffudd (3.Maredudd3, 2.(Unknown2, 1.Gwion1) was born in of Iscoed, Ceredigion, Wales; died on 15 Aug 1275; was buried in Strata Florida Abbey, Ceredigion, Wales. Family/Spouse: Unknown. [Group Sheet] [Family Chart]
Children:
- 5. Llywelyn ab Owain ap Maredudd ab Owain was born in of Cedewain, Powys, Wales; died in 1309.
- 5. Llywelyn ab Owain ap Maredudd ab Owain