In June 684 Ecgfrith, the King of Northumbria, sent an army under Berht to Ireland which laid waste to the plain of Brega, the heart of Fínsnechta's kingdom.
In 695 Congalach and his kinsman Áed mac Dlúthaig (died 701) of the Síl nDlúthaig of Fir Cúl Breg killed Fínsnechta Fledach, the High King of Ireland, and his son Bresal of the Clan Fínsnechtai sept at Grellaigh Dollaith.