Donalbain was a character in William Shakespeare's play Macbeth.
He was the son of the King of Scotland. He appeared in Act II Scene III when Macduff called for him, as well as for Banquo and Malcolm, to wake up after discovering that the King had been murdered. Donalbain asked what was "amiss" upon his arrival with Macduff being the one to inform him of his father's death. (PROSE: The True Tragedie of Macbeth [+]The Shakespeare Notebooks (2014).)