The Clone Empire — Steven L. Kent

Earth, A.D. 2516. The Unified Authority spread human colonies across the Milky Way, keeping strict order with a powerful military made up almost entirely of clones. But when an alien invasion proved too much even for the clones, they alone were blamed for the defeat...

Clone soldier Lieutenant Wayson Harris was born and bred to fight for the U.A. He also possesses a unique independence and an addiction to battle. But after the debacle of the Avatari invasion, he and his brethren were exiled to the far reaches of the galaxy, where the U.A. intended to use them as targets for live-fire training exercises.

Unfortunately for the Unified Authority, the clones it created and taught to fight have founded their own empire. Now Harris will unleash his rage against the might of the U.A. Fleet, leading an army with everything to fight for -- and one thing to die for...

Revenge.