Ethyllt ferch Cynan

Ethyllt ferch Cynan, also known as Ethil, was the heiress to the throne of Gwynedd, Wales.

Her father was King Cynan Dindaethwy ap Rhodri of Gwynedd, and her mother Matilda of Flintshire. Ethyllt was born in 744, most likely in one of Gwynedd's many castles. Little is known of her personal life, but she probably grew up in privilege and comfort.

In 768 she was married to Gwriad ap Elidyr a.k.a. King Guriat of Ynys Manaw (Isle of Man). After the death of her father in 816, the throne was secured by her uncle Hywel ap Rhodri Molwynog. He traveled from the Isle of Man and brought new stability and a new dynasty to Gwynedd, ending many years of Civil War.

Her only son Merfyn ap Gwriad, a.k.a. Merfyn Frych the Freckled became king of the Isle of Man upon his father's death and reigned for 19 years, but was rarely in his kingdom, and left the land weaker, a much easier target for attack. A Hiberno-Viking, Godreg mac Fergus, took over Gwynedd in 836, and the land was not recovered until King Edward I claimed Wales as part of Britain in the 11th century.