Safehold series
Humanity pushed its way to the stars—and encountered the Gbaba, a ruthless alien race that nearly wiped us out. Earth and her colonies are now smoldering ruins, and the few survivors have fled to distant, Earth-like Safehold, to try to rebuild. But the Gbaba can detect the emissions of an industrial civilization, so the human rulers of Safehold have taken extraordinary measures: with mind control and hidden high technology, they've built
...Hell's Foundations Quiver: David Weber's New York Times-bestselling Safehold series begun with Off Armageddon Reef, By Schism Rent Asunder, By Heresies Distressed, A Mighty Fortress and Like a Mighty Army.
TURNING OF THE TIDE
Centuries ago, the human race fought its first great war against an alien race-and lost. A tiny population of human beings fled to distant Safehold. Centuries later, their descendants