Ednyfed Fychan (c. 1170 – 1246), full name Ednyfed Fychan ap Cynwrig, was a Welsh warrior who became Seneschal to the Kingdom of Gwynedd in Northern Wales, serving Llywelyn the Great and his son Dafydd ap Llywelyn. Fychan claimed descent from Marchudd ap Cynan, Lord of Rhos, 'protector' of Rhodri Mawr, King of Gwynedd.
He left the manors of Trecastell, Penmynydd and Erddreiniogin, Anglesey to those of his sons born to his second marriage to Gwenllian, daughter of king Rhys ap Gruffydd of Deheubarth; among these sons was Goronwy (died 1268), founder of the line of the Tudors of Penmynyth. Goronwy served as seneschal of the last Gwynedd king, Llywelyn ap Gruffudd.
Llywelyn the Great, Duke of Gwynedd: 1195: King of Gwynedd, Llywelyn ap Iorwerth, would unify Wales through great war strategy and diplomacy with the kings of England and the princes of Wales. He had troubles with marcher lords, often finding himself fighting in border disputes, while also forming many alliances with rulers in the Marches.