Over the span of forty two years
Isaac Asimov created an epic of Galactic proportions: he showed us the rise and fall of the largest human Empire ever. It consists of seven volumes (about 800,000 words), which although they can be read separately, are closely linked to one another.
/Prelude To Foundation (1988)
[/Forward The Foundation]? (1991)
/Foundation? (1951)
[/Foundation And Empire]? (1952)
[/Second Foundation]? (1953)
Foundation's Edge (1982)
/Foundation And Earth (1983)
see Foundation Trilogy