List of sci-fi novel series, sorted by date - oldest first (all time)

The Thrawn trilogy, also known as the Heir to the Empire trilogy, is a series of best-selling science fiction novels written by Timothy Zhan. The novels are set in the Star Wars Legends universe, approximately five years after the...

The Foundation series is a science fiction series by Isaac Asimov. For nearly thirty years, the series was a trilogy: Foundation, Foundation and Empire, Second Foundation. Asimov began adding to the series in 1981, with two sequel...