In his memoir "I. Asimov" (1994), Asimov explained that following his commercial and critical success with "The Robots of Dawn", he decided to write "Robots and Empire" with the intentions of making Daneel "the real hero of the series", the novel's protagonist; and that "Robots and Empire" would create a bridge to the later volumes of his future history. About this second aim, Asimov said that he was persuaded against it by Lester del Rey and Judy-Lynn del Rey, his long-time friends and the editors of Del Rey Books, who thought that the fans of Asimov's series of novels would rather that Asimov kept the "Robot" and "Empire"/"Foundation" universes separate. On the other hand, his editors at Doubleday Books – his hardcover book publisher – encouraged Asimov to do what deep-down he wanted to do. From then on, Asimov proceeded with his plans for unifying the two series.