Áedán mac Gabráin
At the beginning of the 7th century, Áedán mac Gabráin may have been the most powerful king in northern Britain, and Dál Riata was at its height. Áedán's byname in later Welsh poetry, Aeddan Fradawg (Áedán the Treacherous) does not speak to a favourable reputation among the Britons of Alt Clut, and it may be that he seized control of Alt Clut. Áedán's dominance came to an end around 604, when his army, including Irish kings and Bernician exiles, was defeated by Æthelfrith at the battle of Degsastan.