Off with His Head is a detective novel by Ngaio Marsh; it is the nineteenth novel to feature Roderick Alleyn. It was first published in the USA (by Little, Brown of Boston) in 1956, under the title Death of a Fool, and in the UK (by Collins) in 1957. While sitting comfortably within the "classic puzzle whodunit" form of which Ngaio Marsh was so outstanding an exponent, the novel is highly unusual in its subject matter: England's ancient folkloric rituals in a modern and fast-changing world.