About the MacDougall family
Content supplied by Eddie Sweeney
Clan MacDougall was one of the preeminent Scottish Clans of the early 12th century. The Clan progenitor was Dougall of Argyll and Lorn (~1140-after 1175), the eldest son of Somhairle (Somerled[1]) MacGillebrigte (~1110-1164), Thane of Argyll and Lord of the Isles, by his Viking wife Ragnhild, daughter of the Scandinavian King, Olaf of Man and the Hebrides. Somerled is famed as a powerful Scottish warrior, who played a significant role in the demise of the Viking occupation of Scotland, and who fathered the ancient Clans MacDougall, MacDonald, McAllister, and MacRhuairi. With Somerled’s death at the 1164 Battle of Renfrew, his west coast Kingdom was divided primarily between his eldest sons, Dougall and Ranald.
As Somerled’s eldest son, Dougall inherited the heart of his father’s kingdom, being the castles and estates of Lorn, Benderloch, Lismore, Mull, Coll and Tiree and the smaller inner Hebridean islands, whereas his brother Ranald, and his MacDonald, MacRuraidh and McAllister progeny, inherited the castles and estates of Kintyre, Morvern, Ardnamurchan, Islay and Jura.[2]
The Clan MacDougall weathered significant political and societal challenges between the 12th and 18th centuries wherein they lost much of their lands, power, and prestige, all of which had a direct impact upon the fortunes of the Chiefly family.
Today there remain three branches of the Clan MacDougall, however, the senior male lines of these branches died out in 1953, 1914, and 1888 respectively. The present-day leaders of these families are descended from the female line. They are:
- Clan MacDougall of MacDougall and Dunollie, the main trunk of the Clan MacDougall family tree, and direct descendants of the original MacDougalls of Argyll and Lorn.
- The MacDougalls of Lunga, who are descended from the MacDougalls of Craignicht (Isle of Lismore) and their ancestors the MacDougalls of Raray and Ardmaddie, who branched off from Clan MacDougall of Argyll and Lorn and separated from their MacDougall of Dunollie cousins around 1400ce.
- The MacDougalls of Gallanach who branched off the Dunollie family in 1641 with a grant of the Gallanach lands by Alexander 18th of Clan MacDougall and Dunollie to John MacDougall, 1st of Gallanach.
Work, firstly by Professor Bryan Sykes of Oxford University, and later by geneticists at the University of Illinois, concluded that the genetic marker YP326 was common in men who were male-line descendants of Somerled, and that FGC11896 was associated with men who were male-line descendants of Ranald.
In 2018 this author tested positive for YP326 (the Somerled marker) as well as a new downstream mutation called YP5543 - but was negative for FGC11896 (the Ranald marker). At the time there was only one other Y-DNA tester who was positive for YP5543, and he was a McDougall man.
Around the same time, the author had discovered, by other means, that his biological father was also a McDougall. As a result, The MacDougall DNA Research Project was launched, to test the hypothesis that YP5543 is uniquely inherited by paternal descendants of Dougall of Argyll and Lorn. As of 2026, the project has tested over 400 men and found 68 test-takers who are positive for the YP326>YP5543 signature as well as their own distinctive downstream variants. 14 of these 68 test-takers are residents of the UK and Ireland and the rest are descendants of paternal ancestors who emigrated to the US, Canada, Australia, New Zealand and South Africa.
Extensive research has so far identified two documented male-line descendants of the Chiefly line, one from the Gallanach line and the other from the Raray and Armaddie line. Their most recent common ancestor was Allan ‘ruadh’ MacDougall - 9th of Clan MacDougall and Dunollie (ca 1350-ca 1400), and they descend from his sons John ‘maol’ MacDougall, 10th of MacDougall and Dunollie (ca 1380-1452) and his brother, thought to be Allan ‘dubh’ MacCoulle (also referred to as "Gobhainn Mor”), 1st of Raray and Ardmaddie (ca 1385-after 1425). Their Y-DNA test results show that they each carry a different distinct genetic marker. From this we can conclude that FT51444 was formed in John 'maol' MacDougall or one of his descendants, and similarly, that FT117770 was formed in Allan 'dubh' MacCoulle or one of his descendants.
Continuing Research
The MacDougall DNA Research Project () continues to test MacDougall and derivatively named men, and we are particularly interested in testing the Y-DNA male-line MacDougall descendants with a documented descent from any of the branches of Clan MacDougall. Project details are available at the above website or by contacting the project sponsor and researcher: eddiesweeneyFTDNA@gmail.com.
[1] Wikipedia, Somerled. https://en.wikipedia.org/wiki/Somerled
[2] McDonald, R. Andrew (2008) The Kingdom of the Isles. Scotland’s Western Seaboard c. 1100-1336. Edinburgh. Birlinn Ltd.