Iago ab Idwal ap Meurig was a Prince of Gwynedd

Kingdom of Gwynedd

Gwynedd was one petty kingdom of several Welsh successor states which emerged in 5th-century post-Roman Britain in the Early Middle Ages, and later evolved into a principality during the High Middle Ages. It was based on the former Brythonic tribal lands of the Ordovices, Gangani, and the...

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On the death of Llywelyn ap Seisyll

Llywelyn ap Seisyll

Llywelyn ap Seisyll was a King of Gwynedd and of Deheubarth in north-west and south-west Wales, also called King of the Britons by the Annals of Ulster. Also called Llywelyn ap Seisyllt- Lineage :...

 in 1023, the rule of Gwynedd returned to the ancient dynasty with the accession of Iago, who was a great-grandson of Idwal Foel

Idwal Foel

Idwal Foel ap Anarawd was a King of Gwynedd, referred to as King of the Britons by William of Malmesbury in his Gesta Regum Anglorum. William spells his name as Judwalum in the original Latin ; the Annales Cambriae spell it Iudgual.Idwal inherited the throne of Gwynedd on the death of his...

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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

Gruffydd ap Llywelyn

Gruffydd ap Llywelyn was the ruler of all Wales from 1055 until his death, the only Welsh monarch able to make this boast...

. Iago's grandson Gruffydd ap Cynan

Gruffydd ap Cynan

Gruffydd ap Cynan was a King of Gwynedd. In the course of a long and eventful life, he became a key figure in Welsh resistance to Norman rule, and was remembered as King of all Wales...

 later won the throne of Gwynedd, and because his father, Cynan ap Iago

Cynan ap Iago

Cynan ab Iago was a Welsh Prince, the son of Iago ab Idwal, King of Gwynedd and father of Gruffydd ap Cynan who also became king of Gwynedd....

, was little known in Wales, Gruffydd was styled "grandson of Iago" rather than the usual "son of Cynan".