Na nota do autor no início do "Prelúdio da Fundação", Asimov escreve uma breve cronologia para o universo.
When I wrote "Foundation," which appeared in the May 1942 issue of Astounding Science Faction, I had no idea that I had begun a series of stories that would eventually grow into six volumes and a total of 650,000 words (so far). Nor did I have any idea that it would be unified with my series of short stories and novels involving robots and my novels involving the Galactic Empire for a grand total (so far) of fourteen volumes and a total of about 1,450,000 words.
Aqui está a lista de acompanhamento:
- The Complete Robot (1982). This is a collection of thirty-one robot short stories published between 1940 and 1976 and includes every story in my earlier collection 1. Robot (1950). Only one robot short story has been written since this collection appeared. That is "Robot Dreams," which has not yet appeared in any Doubleday collection.
- The Caves of Steel (1954). This is the first of my robot novels.
- The Naked Sun (1957). The second robot novel.
- The Robots of Dawn (1983 ). The third robot novel.
- Robots and Empire (1985). The fourth robot novel.
- The Currents of Space (1952). This is the first of my Empire novels.
- The Stars, Like Dust- (1951). The second Empire novel.
- Pebble in the Sky (1950). The third Empire novel.
- Prelude to Foundation (1988). This is the first Foundation novel (although it is the latest written, so far).
- Foundation (1951). The second Foundation novel. Actually, it is a collection of four stories, originally published between 1942 and 1944, plus an introductory section written for the book in 1949.
- foundation and Empire (1952). The third Foundation novel, made up of two stories, originally published in 1945.
- Second foundation (1953). The fourth Foundation novel, made up of two stories, originally published in 1948 and 1949.
- Foundations Edge (1982). The fifth Foundation novel.
- Foundation and Earth (1983). The sixth Foundation novel.
Desde que "Foundation and Earth" (1983) foi escrito depois de "The Gods Mesmos" (1972), acho que esta é provavelmente uma boa evidência contra "Os Deuses Mesmos" sendo planejados como parte da série.