The Cenél Loairn derive their descent from Loam, son of Erc, a king of Dal Riada in the fifth century. They originally inhabited the present districts of Loin (named for them) and Mull, with the adjacent mainland and island territory to the north and west. This territory comprised the northern part of Scottish Dal Riada, and when the time came for expansion, the Cenél Loairn migrated up the Great Glen. The chief kindred branches of the Cenél Loaimn were the Clann Duibhne, or Campbells, the MacGillivrays and Maclnneses, the Cenél Baodan, or MacLeans, the MacNaughtens, the MacNabs, the Clan Chattan, and the Carnerons, MacGillonies, MacMartins and MacSorleys.
The Clann Duibhne or Campbells (Caimbeul), the most powerful clan in Argyle and one of the most powerful in Scotland, descend from the issue of the thirteenth century marriage between Sir Gillespie Campbell and the heiress of Duncan Mac Duibhne of Lochawe. Thus did the Campbells inherit the leadership of the Clann Duibhne, whose name they retained notwithstanding the fact that they, like the Galbraiths of Loch Lomond, were by origin Strathclyde Britons from around Dunbarton, where they were still important to the end of the thirteenth century. Ethnically these Strathclyde Britons were Laiginian, being descended from a Dumnonian influx from Ireland.
Ancient inhabitants of Tyrone, Donegal, and Monaghan were ascribed to the Scoti or the Erdini, the inhabitants of this district of Fermanagh.
The senior line of the Campbells, descended from Sir Gillespic’s older brother Duncan, were the MacArthurs (Clann Artair) of Loch Fyne and Lochawe. The MacArthurs lost power after their chief, lain MacArthur, "a great prince among his own people and leader of a thousand men," was beheaded by the Stewart King James I in 1427. Afterwards they lived under the protection of their Campbell kinsmen. As for the Campbells themselves, they rose to preeminence in Argyle under royal patronage following the downfall of the MacDonalds’ Lordship of the Isles. The chief of the Lochawe line, the main stem of the family, was created Duke of Argyle in 1457. The Campbells of Glenorchy, later Earls of Breadalbane (1681), descend from the grandson of Sir Gillespie, while those who inherited Cawdor (in Moray) descend from the third son of the second Earl of Argyle. The Campbells became infamous for their political pragmatism, which led them to commit acts of brutality and treachery against neighboring clans, notably the MacGregors and the MacDonalds of Glencoe.
The Cenél Baodan, or MacLeans (Mac Giolla Eoin) descend from Baodan, great-grandson of Loarn, king of Dal Riada. The clan was originally settled in Morvern, where they gave their name to a district, and one of their early ancestors was abbot of the nearby Isle of Lismore. In later times they migrated up the Great Glen into Moray, and later still, about 1160, they were one of several clans transferred to the Scone area (Tayside in Perthshire) by Malcolm IV the Maiden. Their eponymous ancestor was Gillean (Giolla Eoin) of the Battleaxe, who lived during the reign of Alexander III (1249—1283), and fought at the Battle of Largs in 1263. Gillemoir MacLyn of Perthshire, son of Gillean, settled in Loin, and his son, a supporter of Robert Bruce, was named "Malise," which was the favorite name of the earls of Strathearn (Perthshire) at that time, and almost unique to them. Malise’s grandson, Ian Dhu MacLean, settled in Mull, and was the father of Lachlan Lubanach, progenitor of the MacLeans of Duart, the chief family of the clan. He was also father of Eachin Reganach, progenitor of the MacLaines of Lochbuie, and the MacLaines disputed the chiefship with the Duart branch on the claim that Eachin was elder to Lachlan, though the chiefship was settled on the Duart branch by tanistry. Both of these brothers lived in the reign of Robert II.
The clan held wide power in the Hebrides, as allies of the MacDonalds, under the Lord of the Isles. One of Eachin’s Sons, Charles MacLean, settled in Glen Urquhart, in Moray, and was the founder of the Clann Thearlaich, also known as the MacLeans of the North. The Clann Thearlaich joined the Clan Chattan confederacy about 1460, but nonetheless appealed to MacLean of Duart, as their hereditary chief, for protection against harassment by the Chisholms. The Duart chief recognized their rights as clansmen, and forced the Chisholms to desist.
The Clan Chattan (Clann Chatain) was a confederation of clans in the Moray areas of Lochaber, Strathnairn and Badenoch. The main stem of the clan included the MacPhersons, Davidsons, MacBeans or MacBains, Cattanachs, and by inheritance, the MacKintoshes. These clans were joined by others, of different origin, who at various times applied for protection of the MacKintosh chiefs, who were also captains, or high chiefs, of the Clan Chattan confederation. These included the MacGillivrays, Maclntyres, MacLeans, MacQueens, MacAndrews, and others.
The MacKintoshes (Mac an Toisich) are paternally an offshoot of the Clan MacDuff of Fife, whose chiefs, the earls of Fife, held vast territory in Moray during the thirteenth century. Rothiemurchus, the earliest known territory of the Mackintoshes, was surrounded by this territory. In 1291, Angus, sixth chief of the MacKintoshes, married Eva, daughter and only child of Dougal Dall, sixth chief of the Clan Chattan. The Clan Chattan line stretched back to the first chief, Gillechattan Mor, heir of the co-arbs of the abbey of Kilchattan on the Isle of Bute, the special abbey of the Cenél Loairn. The line of this Gillechattan Mor, whose name means "great servant of St. Cattan" (the patron saint of the Abbey of Kilchattan) acquired land in Lochaber and Badenoch, probably by Pictish succession. This may explain the use of the wildcat as the heraldic beast of the Clan Chattan, informally referred to as the Clan of the Cats: St. Cattan’s name means "little cat," and the Northern Picts had an ancient totemistic connection to the cat (hence the name of the province of Caithness in northern Scotland—Sutherland). As for the MacKintoshes, since no surname was associated with the Clan Chattan chiefship in these virtually pre-surname days in Scotland, the new line of MacKintoshes kept their name, but continued as captains of the Clan Chattan.
The Clann Fhionnlaigh or Farquharsons (Mac Fhearchair) of Invercauld in Aberdeenshire are descended from the Shaws of Rothiemurchus, cadets of the MacKintoshes. They inherited Invercauld from the MacHardys.
The Cenél nGabrain originally dwelt south of the Cenél Loairn in the island districts of Jura, Bute, and Arran, and the mainland districts of Cowal and Kintyre. They derive their descent from Gabhran, King of Dal Riada in the sixth century. They were the chief clan of the Dal Riada, and merged with the Pictish Royal House in the ninth century. Their chief descendants include the Fergusons, MacKerseys, MacFies, MacGregors, MacKinnons and MacQuarries.
The Siol Alpin is the name of a group of clans traditionally connected by their mutual traditional descent from Kenneth MacAlpin (first king of the united kingdom of Picts and Scots in the ninth century), a tradition which simply indicates that they were all of generally "South Argyle" Dalriadic stock. These families include the MacGregors (Mac Grioghair), an "outlaw" clan of the Argyle-Perthshire border, many of whom were forced to assume aliases, and to which clan belonged the famous eighteenth century adventurer "Rob Roy" MacGregor (alias Campbell); The MacFies or MacPhies (Mac Dhuibhshithe) of Colonsay; the MacKinnons (Mac Fhionghuin) of Mull, Skye and Iona (the last abbot of Iona in 1550 was a MacKinnon), and the MacQuarries (Mac Guadhre) of Ulva and Mull in the Hebrides, who followed the MacLeans after the downfall of the MacDonald lords of the Isles. The MacFies lost Colonsay after joining in the rebellion of Sir James MacDonald in 1615, after which some followed the MacDonalds, while others settled in Lochaber and followed the Camerons. The MacKinnons and MacFies were closely connected with the Abbey of Iona, being the local clan-stock of the lona area. The MacKinnons became erenaghs, or hereditary abbots, of Iona after the failure of the original Cenél Conaill line around 1200. The MacPies may descend from the "Dubhsidhe" who was Iector of Iona in 1164. The MacFies held part of the Isle of Jura, and sat on the Council of the Isles advising the MacDonald lords thereof. After the downfall of the Lordship of the Isles in the late fifteenth century, the main branch of the MacFies followed the MacDonalds of Islay, and a sixteenth-century branch settled in Ulster.
The Osraighe (including the Uí Duach and the MacGilpatricks) were of the same stock as the Ulaid, being descended from Oengus Osraigh, ancestor of the Dal bhFiatach.
The Osraighe migrated to Ossory (County Kilkenny), which they gave their name to, in very early times. For the purpose of incorporating the separate territory of Ossory within over-kingdom of Leinster, the Osraighe were later given transparent descent from the Laigin. The Osraige gave rise to the medieval dynasty of Ossory, the MacGilpatricks or Fitzpatricks (Mac Giolla Phadraig), and to their collateral kinsmen the Uí Duach or O’Brennans (0 Braonain). The MacGilpatricks descend from Giolla Phadraig, son of Donnchadh, lord of Ossory in the tenth century. They originally ruled over all Kilkenney and part of Leix as well, but after the Anglo-Norman invasion their territory was greatly encroached upon by the Butlers and others, and afterwards they held a greatly reduced territory in the very north of County Kilkenny, alongside their kinsmen the O’Brennans.