Donald 'Bane' (Fair) was the younger brother of Malcolm III, and the second son of Duncan I.
He succeeded Malcolm III in 1093, at the age of 60, after driving out Malcolm's sons and claiming the crown on the basis of tanistry.
Donald was deposed by Duncan II in May 1094, with the assistance of William II (Rufus) of England; Donald regained the throne soon afterwards when Duncan was killed in November that year. Donald then seems to have shared his rule with his nephew Edmund (Donald in Scotia, Edmund in Lothian and Strathclyde).
In 1097, Malcolm III's son Edgar invaded Scotland with help from William II of England, and Donald was defeated and deposed once more.
Accounts of his fate differ, but according to one version he was blinded and kept prisoner until his death at Rescobie, Angus in about 1100. Edmund was pardoned and became a monk.