Merlin and Nimuë was one of Burne-Jones's favourite Arthurian themes. He discovered a copy of the 1817 edition of Sir Thomas Malory's Morte d'Arthur in a Birmingham bookshop in 1855. Burne-Jones's first opportunity to paint an Arthurian subject was a mural for the old Debating Hall of the Oxford Union in 1857. He selected Merlin and Nimuë.
This sketch is a study for a later version of the subject, the celebrated Beguiling of Merlin (Lady Lever Art Gallery, Port Sunlight), exhibited at the Grosveor Gallery in 1877. Maria Zambaco, Burne-Jones's muse, may have been the model for this head study. It relates closely to the finished oil in which Nimuë acts the femme fatale, luring the magician to his doom. Merlin is depicted as curiously acquiescent, unable to prevent Nimuë from capturing his heart and diminishing his powers, an image perhaps reflecting Burne-Jones's own feelings towards Maria.
Studies for The Beguiling of Merlin are in the Fitzwilliam Museum, Cambridge, the Bancroft Collection at Wilmington, Delaware, and elsewhere.