Darknesses — L.E. Modesitt Jr.

Millennia ago, a magical disaster caused the fall of a civilization, the end of a golden age. New civilizations emerged from the ancient destruction and chaos, knowing little of the past or the disaster. Corus today is a world of contending countries, humans, and supernatural creatures. It is a place of magical powers, and of a few people who are talented enough to use them. Alusius, a captain of the Twenty-first Company, faces new challenges, both military and magical. A would-be conqueror has somehow revived sorcerous creatures of legend to assist in his crusade to reunite the continent under his rule--Publisher marketing.