[5] However, the correctness of the archive's assertion is challenged in Haddan and William Stubbs' authoritative Councils and Ecclesiastical Documents Relating to Great Britain and Ireland, where it is noted that "the earliest historical testimony to a Dean at Bangor is 1162".
[8] The largely fictional stories of ancient Britain written by Geoffrey of Monmouth use the names of many historical personages as characters, and the use of these names is a literary convenience made in order to advance the plot of Geoffrey's stories.
One of these stories uses the names of Iago's son Cadfan and other contemporary people, telling of how a certain Edwin spent his exiled youth in Gwynedd, growing up alongside Iago's grandson, the future King Cadwallon.
[9] Nevertheless, a "traditional" story arose blending Geoffrey's fiction with known history, implying that the future King Edwin of Northumbria had actually spent his youth in Gwynedd, growing up alongside Iago's grandson, the future King Cadwallon.
Edwin would eventually ally himself with Rædwald of East Anglia in 616, defeating and killing Æthelfrith and becoming one of Northumbria's most successful kings.