Many writers have assumed that MacSween and MacQueen are virtually synonymous, but this is not the case.
The original MacSweens (‘son of Sweyn’, a Norse name) held the Isle of Arran, Knapdale, and parts of Kintyre until 1262, when they lost most of them to Walter Stewart, Earl of Mentieth.
During the Wars for Scottish Independence, the MacSweens allied with the MacDougalls of Argyll and Lorn, who sided with the Comyns in their civil war with the forces of Robert the Bruce because of kinship by marriage. After a failed invasion of Argyllshire with their longtime allies at the behest of Edward II of England, the MacSweens dispersed from their homeland.
The major contingent of MacSweens made their way to Ireland, where they became known as the MacSweeneys and served as gallowglasses to the O’Donnells of Tir-Connaill (Co. Donegal). There were eventually three branches in Tir Connaill.
Gallowglasses were professional heavy infantry soldiers mercenaries from Scotland’s Western Islands (Hebrides) and the western coast regions of northern Scotland. Their craft had been developed under the Norse and Danish kings of the Isles.
The MacSweens, of course, were not the only highlanders and islanders to follow that course. A branch of the Mackays of Strathnaver, for example, who had migrated to Kintyre and become the MacCoys crossed the Irish Sea to settle what became Co. Armagh as gallowglasses. Likewise for the MacDonnells of Antrim who came from Islay in the Hebrides Islands. A branch of the MacLeods known as MacCabes served as gallowglasses to the O’Rourkes and O’Reillys of Breifne.
Other major gallowglass clans in Ireland included the McDowells, originally MacDougalls of Lorne, the MacRuaris originally from the Isle of Bute, and the MacSheehys from Kintyre.
Another group made their way to Raasay, which they held under the MacDonalds until they were removed by the MacLeods of Lewis in 1518. Most of these MacSweens migrated to the MacDonald lands of Sleat on the Isle of Skye, where they spelled their surname MacSwain and later many anglicized it as Swan.
Those of the clan who remained stayed in Otter near Loch Fyne, where they became known as the MacEwans. They lost their lands to the Campbells of Lochow (later of Argyll) in 1493.
The family of MacQueen had an entirely different origin. From northern Trotternish on the Isle of Skye, they began as a sept of the MacDonalds of Sleat and eventually became their own clan; their anglicized name derives from “Mac Cuithean”, which is a version of the Gaelic name for the MacDonalds of Sleat, Clan Uisdean.
A sept of Clan Chattan known as the MacQueens of Corrybrough, also known as Clan Revan, after their founder of that surname. Some holding them to be a branch of the MacQueens of northern Trotternish, others to be a branch of the MacSweens, the former being more likely.
(Note: The MacSweeneys of Ireland recommend if its members wear tartan, they wear that of the MacQueens of Corrybrough.)