Alexander of Islay or Alexander MacDonald is a medieval Scottish nobleman, who succeeds his father Domhnall of Islay as Lord of the Isles (1423–1449) and rises to the rank of Earl of Ross (1437–49).
His lively career, especially before he attained the earldom of Ross, leads Hugh MacDonald, the seventeenth century author of History of the MacDonalds, to commemorate him as "a man born to much trouble all his lifetime".
Alexander allies himself with King James I of Scotland against the power of the Albany Stewarts in 1425 but, once the Albany Stewarts are out of the way, quickly finds himself at odds with the new king.
War with King James will initially prove Alexander's undoing, and will see the King's power in Scotland greatly increased, but at the Battle of Inverlochy Alexander's army prevails against the forces of the King.
Alexander dies in 1449, having greatly extended his family's landed wealth and power.
He is buried, not in the Isles of his ancestors, but at Fortrose Cathedral in his mainland Earldom of Ross.
