Momo, also known as The Grey Gentlemen or The Men in Grey, is a fantasy novel by Michael Ende, published in 1973. It is about the concept of time and how it is used by humans in modern societies. The full title in German (Momo oder Die seltsame Geschichte von den Zeit-Dieben und von dem Kind, das den Menschen die gestohlene Zeit zurückbrachte) translates to Momo, or the strange story of the time-thieves and the child who brought the stolen time back to the people. The book won the Deutscher Jugendliteraturpreis in 1974.