 He was killed, along with his son Bresal, by his kinsmen Áed mac Dlúthaig and Congalach mac Conaing Cuirre at Grellaigh Dollaith.According to the "Annals of Tigernach", this occurred in battle, but the "Fragmentary Annals of Ireland" state that Finsnechta was murdered in a tent by Congalach.Congalach succeeded Fínsnechta as King of Brega, and Loingsech mac Óengusso, of the northern Cenél Conaill branch of the Uí Néill, was the next High King.