Alasdair Mac Colla Chiotaich MacDhòmhnaill, also known by the English variant of his name Sir Alexander MacDonald, was a military officer best known for his participation in the Wars of the Three Kingdoms, notably the Irish Confederate Wars and Montrose's Royalist campaign in Scotland during 1644–5. A member of the Gaelic gentry of the Clan MacDonald of Dunnyveg, a branch of the Clan Donald active in the Hebrides and Ireland, Mac Colla is particularly notable for the very large number of oral traditions and legends which his life inspired in the Highlands.

The Irish Confederate Wars, also called the Eleven Years' War, took place in Ireland between 1641 and 1653. It was the Irish theatre of the Wars of the Three Kingdoms, a series of civil wars in the kingdoms of Ireland, England and Scotland – all ruled by Charles I. The conflict had political, religious and ethnic aspects and was fought over governance, land ownership, religious freedom and religious discrimination. The main issues were whether Irish Catholics or British Protestants held most political power and owned most of the land, and whether Ireland would be a self-governing kingdom under Charles I or subordinate to the parliament in England. It was the most destructive conflict in Irish history and caused 200,000–600,000 deaths from fighting as well as war-related famine and disease.