Cenél nGabráin in the context of "Fergus Mór"

Dál Riata or Dál Riada (also Dalriada) (/dælˈriːədə/) was a Gaelic kingdom that encompassed the western seaboard of Scotland and north-eastern Ireland, on each side of the North Channel. At its height in the 6th and 7th centuries, it covered what is now Argyll ("Coast of the Gaels") in Scotland and part of County Antrim in Northern Ireland. After a period of expansion, Dál Riata eventually became associated with the Gaelic Kingdom of Alba.

In Argyll, it consisted of four main kindreds or tribes, each with their own chief: the Cenél nGabráin (based in Kintyre), the Cenél nÓengusa (based on Islay), the Cenél Loairn (who gave their name to the district of Lorn) and the Cenél Comgaill (who gave their name to Cowal). The hillfort of Dunadd is believed to have been its capital. Other royal forts included Dunollie, Dunaverty and Dunseverick. Within Dál Riata was the important monastery of Iona, which played a key role in the spread of Celtic Christianity throughout northern Britain, and in the development of insular art. Iona was a centre of learning and produced many important manuscripts. Dál Riata had a strong seafaring culture and a large naval fleet.

The Cenél nÓengusa were a kin group who ruled the island of Islay, and perhaps nearby Colonsay, off the western coast of Scotland in the early Middle Ages.

The Senchus fer n-Alban, a census and genealogy of the kingdom of Dál Riata, lists the Cenél nÓengusa as one of the three kin groups making up the kingdom in Argyll. The others were the Cenél nGabráin of Kintyre and the Cenél Loairn of Lorn. A fourth group, the Cenél Comgaill, of Cowal and the Isle of Bute, later split from the Cenél nGabráin. The Senchus portrays Dál Riata as it existed in the mid-seventh century.