Majordomo and chief aide to the God Emperor Leto Atreides II at the time of his death, in the 4th book of the Dune saga. A product of the breeding program taken over by Leto from the Bene Gesserit. Like all those whom Leto trusted most, Moneo was a rebel in his youth, and came to trust implicitly in Leto, and thus in himself. He displays his ultimate love for his daughter, Siona Atreides, by sending her on a test which she may not survive. However, if she does survive, she will gain her own humanity, as Moneo himself did by passing the test in his own youth.