He is described by the witches as "lesser than Macbeth, and greater"
In scene three, when Banquo receives the three predictions from the witches he 
is told that he will be "Lesser than Macbeth, and greater / Not... [DOC] [TLE] Macbeth Act 1 Scene 3 - The Witches meet Macbeth [PAR] Third Witch, All hail, Macbeth, thou shalt be king hereafter!