Lennox is a young Thane attending on Duncan.
He accompanies Macduff the morning of Duncan’s murder, and notes that he cannot remember as stormy a night as the preceding one. He joins Macbeth’s court, but is soon convinced of the usurper’s guilt, which he cautiously exposes to similarly-minded lords in ironical phrases. He still stays with Macbeth, however, bringing him the news of Macduff’s flight. He is one of the Thanes who deserts Macbeth once Malcolm invades, bringing reinforcements to Malcolm’s army, and is well-informed of who is present with Malcolm.