Cumhall (; ) or Cumhall mac Trénmhoir ("son of Trénmór/Tréanmór" meaning "strong-great") is a figure in the Fenian Cycle of Irish mythology, a leader of the fianna and the father of Fionn mac Cumhaill.
Genealogy
The most important text regarding the family of Finn (son of Cumaill) is Fotha Catha Chnucha ("The Cause of the Battle of Cnucha"), as it is contained in the ancient parchment Lebor na hUidre (LU), dated to the 12th century. Otherwise, the next most important tract is the Macgnímartha Finn ("The Boyhood Deeds of Fionn") copied in a 15th-century manuscript.
According to the Fotha Catha Chnucha, Cumhall mac Trénmhoir was son of a petty king, and served the High King Conn Cet-Chathach "of the Hundred Battles". Cumhall was also Conn's half-uncle, his mother being the mother of Conn's father,. daughter of the druid Tadg mac Nuadat, but Tadg refused him, so Cumhall forcibly carried away Muirne in elopement.
In Fotha Catha Chnucha Cumhall's wife was the granddaughter to Nuadat who was a druid to king Cathair Mór, but she was granddaughter to Núadu of the Tuatha Dé Danann according to a passage in the Acallamh na Senorach. Also where the former work gives Almu daughter of Becan as Nuadat's wife,