King Mac Bethad mac Findlaích (anglicised as Macbeth) was King of the Scots (also known as the King of Alba, and earlier as King of Moray and King of Fortriu) from 1040 until his death in 1057.
Sir Quackly McDuck sided with King Macbeth, defending him in the civil war of 1057. In return, he was given a chest of gold.
In "The Last of the Clan McDuck", Macbeth is depicted to be dragged outside of Castle McDuck in order to be executed, symbolizing his defeat and death following the English Invasion.
Etymology The name Mac Bethad (or, in modern Gaelic, MacBheatha), from which the anglicized "MacBeth" is derived, means "son of life". Although it has the appearance of a Gaelic patronymic it does not have any meaning of filiation but instead carries an implication of "righteous man" or "religious man". An alternative proposed derivation is that it is a corruption of macc-bethad meaning "one of the elect".