The Visionary Heads is a series of black chalk and pencil drawings produced by William Blake after 1818 by request of John Varley, the watercolour artist and astrologer. The subjects of the sketches, many of whom are famous historical and mythical characters, appeared to Blake in visions during late night meetings with Varley, as if sitting for portraits. The drawings are contained in three sketchbooks and there are a number of loose leaves indicating the existence of a fourth sketchbook. Like most of Blake's other works, they have been subject to academic scrutiny and study.
Among the Visionary Heads drawn by Blake are David, Solomon, Uriah and Bathsheba, Nebuchadnezzar, Saul, Lot, Job, Socrates, his wife Xantippe, Julius Caesar, Christ, Muhammad, Merlin, Boadicea, Charlemagne, Ossian, Robin Hood, Caractacus, King Edward I, his Queen Eleanor, Black Prince, King Edward III, William Wallace, Wat Tyler, Roger Bacon, John Milton, Voltaire, as well as Devil, Satan, "Cancer", The Man Who Built the Pyramids, The Portrait of a Man who instructed Mr Blake in Painting &c in his Dreams, etc. The most famous of that series is Blake's painting of The Ghost of a Flea, made after the Visionary Head of The Ghost of a Flea.