Not to be confused with Iago ab Idwal ap Meurig
Iago ab Idwal (ruled 950–979) was a King of Gwynedd and possibly Powys, also referred to as "King of the Britons" by the Annals of Ulster.
Iago was the son of Idwal Foel, and on his father's death in battle in 942 would have expected to succeed to the rule of Gwynedd together with his brother Ieuaf ab Idwal. However Hywel Dda King of Deheubarth took the opportunity to invade Gwynedd and dispossess the young princes.
On Hywel's death in 950 Iago and Ieuaf were able to claim the throne of Gwynedd, driving out the sons of Hywel. Fighting continued between the two dynasties, with Iago and Ieuaf raiding as far south as Dyfed in 952 and the sons of Howell raiding as far north as the Conwy valley in 954 before being defeated in battle at Llanrwst and chased back to Ceredigion.
The sons of Idwal quarreled and Iago took Ieuaf prisoner in 969. Despite a temporary defeat in 974 Iago ruled Gwynedd until 979 when he in turn was taken prisoner by Ieuaf's son, Hywel ab Ieuaf, who took over his kingdom. There appears to be no record of Iago's fate.
| Preceded by Hywel Dda |
Prince of Gwynedd 950–979 |
Succeeded by Hywel ab Ieuaf |