• Died: 501

  Research Notes:

The historical record, such as it is, consists of an entry in the Annals of Tigernach, for the year 501, which states: Feargus Mor mac Earca cum gente Dal Riada partem Britaniae tenuit, et ibi mortuus est. (Fergus Mór mac Eirc, with the people of Dál Riata, held part of Britain, and he died there.) However, the forms of Fergus, Erc and Dál Riata are later ones, written down long after the 6th century. The record in the Annals has given rise to theories of invasions of Argyll from Ireland, but these are not considered authentic.

Fergus is also found in the king lists of Dál Riata, and later of Scotland, of which the Senchus Fer n-Alban and the Duan Albanach can be taken as examples. The Senchus states that Fergus Mór was also known as Mac Nisse Mór. These sources probably date from the 10th and 11th centuries respectively, between 30 and 40 generations after Fergus may have lived.

The Senchus and the Duan name Fergus's father as Erc son of Eochaid Muinremuir. A Middle Irish genealogy of the kings of Alba gives an extensive genealogy for Fergus: [Fergus] m. h-Eircc m. Echdach Muinremuir m. Óengusa Fir m. Feideilmid m. Óengusa m. Feideilmid m. Cormaicc, and a further forty-six generations here omitted.