Cumhaill

Captain of the Fianna (rígfhéinnid) and chieftain of Clan Baiscne. Cumhaill (Cumhall or Cool) was the son of Trenmor and descendant of Baíscne. Cumhaill was also the brother of Crimmal.

Cumhaill married Muirenn, daughter of Tadg and granddaughter of Nuada of the Silver Hand. Cumhaill was the father of Finn.

Before his son was born, Goll Mac Morna had challenged Cumhaill for the leadership of the Fianna. Cumhaill's father-in-law had opposed his daughter marriage to Cumhaill. Tadg conspired with Goll to overthrow and kill Cumhaill.

A clan war was fought at Cnucha (Knock), not far from Tara. Tadg used his magic to confuse and strike fear upon Clan Baiscne. Cumhaill began to suffer from sudden weakness due to Tadg's magic. Cumhaill managed to wound Goll, taking out one of his eyes, but Cumhaill was killed by Lia, lord of Luachar.