Foundation and empire - Isaac Asimov

The Foundation novels of Isaac Asimov are one of the great masterworks of science
fiction.
Unsurpassed for their unique blend of nonstop action, daring ideas, and
extensive world-building, they chronicle the struggle of a courageous group of men
and women to preserve humanity's light against an inexorable tide of darkness and
violence.

Led by its founding father, the great psychohistorian Hari Seldon, and
taking advantage of its superior science and technology, the Foundation has survived
the greed and barbarism of its neighboring warrior-planets.
Yet now it must face
the Empire-still the mightiest force in the Galaxy even in its death throes.
When
an ambitious general determined to restore the Empire's glory turns the vast Imperial
fleet toward the Foundation, the only hope for the small planet of scholars and scientists
lies in the prophecies of Hari Seldon.

But not even Hari Seldon could have predicted
the birth of the extraordinary creature called The Mule-a mutant intelligence with
a power greater than a dozen battle fleets . . . a power that can turn the strongest-willed
human into an obedient slave.