McAllister of Ireland
McAllister is a surname from Scotland and Northern Ireland which is the anglicized form of Gaelic Mac Alasdair or son of Alasdair. Alasdair was the son of Donald of Islay, forefather of Clan Donald and great-grandson of Somerled, King of the Isles. For many generations, the Western Isles of Scotland had been under the control of the King of Norway. His Viking marauders had settled in the Gaelic Isles, maintaining coastal settlements and using these as a base for attacks onto the mainland and into Ireland. The Celts regained control of the Isles in the 12th century under the forceful leadership of Somerled. While the Norse continued to claim supremacy, the Isles were ruled as a virtually independent realm by Somerled's descendants.
Somerled divided his lands among his sons, Ranald, Dugall, and Angus. Ranald received Islay and Kintyre and the southern Isles. Ranald and Dugall, however, disagreed over the Island of Mull and this dispute was to lead to bitter relations between the "MacDugalls" and Ranald's family. While Ranald was a religious and peaceful man, his sons Donald and Rauri inherited the warlike attributes of their grandfather. As early as 1211 they led a raiding party of 76 galleys to plunder the Irish town of Derry. Donald of Islay had inherited more than vast landholdings. He had become the leader of one of the few remaining Gaelic realms. Around 1249 the rule of the Isles passed to Donald's eldest son, Angus Mór. Donald's second son, Alasdair Mór, appears to have either inherited lands in Antrim, or was involved in military affairs in Ulster, as he spent much of his adult life in Ireland.
Clan Donald prospered and became one of the largest Scottish clans. They were dominant in western Scotland until 1493, when their lands were forfeited to the Crown. At this point a number of groups that had been aligned with the Clan Donald emerged as independent clans, among them the MacAlasdairs (or MacAlisters). The MacAlasdairs appear to have worn the MacDonald tartan as late as 1745. While the MacAlasdairs were never a very large clan, they provided loyal and often distinguished support to the Clan Donald throughout the centuries. Clan Alasdair continued to have close ties to northern Ireland, particularly Antrim. Today the greatest numbers of the name McAllister are to be found in the Irish counties of Antrim, Londonderry, Fermanagh and Dublin.