[1] Loingsech is first mentioned in the annals of Ireland under the year 672 when he defeated Dúngal mac Máele Tuil of the Cenél mBógaine who was slain.
[3] His accession to lordship of the Cenél Conaill is not mentioned, but the death of his uncle Ailill Flann Esa (died 666) is recorded during the plague years.
[5] The record in the Annals of Ulster may show that Congalach mac Conaing Cuirre (died 696) of the Síl nÁedo Sláine branch of the southern Uí Néill was a candidate for the high kingship after the killing of Fínsnechta, in competition with Loingsech.
[11] Loingsech was killed in 703, in the Battle of Corann (in Southern Co.Sligo) against the men of Connacht led by their old king Cellach mac Rogallaig (died 705).
A quatrain attributed to the old king Cellach states:[13] "For his deeds of ambition, on the morning he was slain at Glais Chuilg; I slew Loingseach there with a sword, the monarch of all Ireland round.