Iago ab Idwal ap Meurig
Very little is known about the reign of Iago. He was killed by his own men in 1039 and replaced by Llywelyn ap Seisyll's son, Gruffydd ap Llywelyn. Iago's grandson Gruffudd ap Cynan later won the throne of Gwynedd, and because his father, Cynan ab Iago, was little known in Wales, Gruffudd was styled "grandson of Iago" rather than the usual "son of Cynan".
- John Edward Lloyd (1911). A history of Wales: from the earliest times to the Edwardian conquest. Longmans, Green & Co.
Llywelyn ap Seisyll
| Prince of Gwynedd and King of Powys
Gruffydd ap Llywelyn