Killed by his nephew ca. 559 (Williamson, David. Debrett's kings and queens of Britain. Topsfield, Mass. : Salem House Publishers, 1986, pg. 228).
King of Scots of Argyle. "Gabran the Treacherous." King of Dal Riada.

Gabrán's chief importance is as the presumed ancestor of the Cenél nGabraín,[4] a kingroup which dominated the kingship of Dál Riata until the late 7th century and continued to provide kings thereafter. Kings of Alba and of Scotland traced their descent through Gabrán to his grandfather Fergus Mór, who was seen as the ultimate founder of the royal house as late as the 16th and 17th centuries, long after the Gaelic origins of the kingdom had ceased to have any real meaning.

Unlike the Cenél Loairn, the Senchus Fer n-Alban does not list any kindreds within the Cenél nGabraín. However, probable descendants of Gabrán, such as Dúnchad mac Conaing and his many kinsmen, would appear to have disputed the succession with the descendants of Eochaid Buide grandson of Gabrán, so that this absence of explicit segments in the kindred may be misleading. A genealogy of David I of Scotland in the Book of Ballymote notes the following divisions:

After Áedán mac Gabráin, between the main line, called "the sons of Eochaid Buide" and "the children of Cináed mac Ailpín", and the "sons of Conaing"
After Eochaid Buide, between the main line and the "children of Fergus Goll" and the "children of Connad Cerr ... or the men of Fife", although modern studies make Connad Cerr a member of the Cenél Comgaill
After Eochaid mac Domangairt, between the main line and the Cenél Comgaill
The domain of the Cenél nGabraín appears to have been centred in Kintyre and Knapdale and may have included Arran, Jura and Gigha. The title king of Kintyre is used of a number of presumed kings of the Cenél nGabrain. Two probable royal sites are known, Dunadd, which lies at the northern edge of their presumed lands, and Aberte (or Dún Aberte), which is very likely the later Dunaverty on the headland beside Southend, Kintyre.

Kilmartin may have been an important early Christian site by reason of its proximity to Dunadd and its dedication to Saint Martin of Tours, as may Kilmichael Glassary. However, there appears to be no religious site of the importance of Lismore in the lands of the rival Cenél Loairn (wikipedia)