|Llywelyn ap Seisyll King of Gwynedd and of Deheubarth 
Llywelyn ap Seisyll King of Gwynedd and of Deheubarth  24
Noted events in his life were:
• Acceded: King of Gwynedd, 1018. Llywelyn won control of Gwynedd in 1018 when he defeated Aeddan ap Blegywryd in battle, killing him and his four sons.
• Acceded: King of Deheubarth, 1022. He later gained control of Deheubarth, defeating Rhain , an Irish pretender who claimed to be the son of Maredudd ab Owain , at Abergwili in 1022.
Llywelyn married Angharad Ferch Maredudd Queen of Powys  [MRIN: 2044], daughter of Maredudd ap Owain King of Deheubarth  and Unknown.