The annals record a battle in 791 at Tailtiu, site of a major Uí Néill oenach, the oenach Tailten. The summoning of this gathering was one of the prerogatives of the High King at which he would demonstrate his power and standing. Whether Áed brought an army south to disturb the oenach, or whether the conflict was provoked by Donnchad, is unknown. The outcome was that Áed fled from Tailtiu and was pursued perhaps as far as Slane. Several of Áed's allies are said to have been killed, including the kings of two branches of Uí Chremthainn, an Airgíalla dynasty whose lands lay around Clogher and Clones.