Galactic Empire (series)

The Galactic Empire series (also called the Empire novels or trilogy) is a science fiction sequence of three of Isaac Asimov's earliest novels, and extended by one short story. They are connected by their early place in his published works and chronological placement within his overarching Foundation Universe, set around the rise of Asimov's Galactic Empire, between the Robot and Foundation series to which they were linked in Asimov's later novels.