Belisarius Ii: Storm At Noontide( Series - Belisarius )

"Destiny's Shield: " Evil from beyond time: The Malwa Empire squats like a toad across sixth century India, commanded by ruthless men with depraved appetites. But the thing from the distant future that commands them is far worse. Those who oppose the purulent Hell the Malwa will make of Earth have sent a crystal, Aide, to halt their advance. Aide holds all human knowledge--but cannot act by himself. That requires Count Belisarius, the greatest general fo the age and perhaps of all ages, who must outwit the evil empire--and then, when there is no longer room to maneuver, to meet it sword-edge to sword-edge, lest evil beyond human conception rules the world forever.

"Fortune's Stroke: " Link, the supercomputer from a future that should not, must not exist has used terror and gunpowder weapons to forge the Malwa Empire on the Indian subcontinent. Aide and Belisarius have led the armies of Byzantium and blunted the first assault of the Malwa hordes. Now he and his allies from all the world face overwhelming numbers in a ring that tightens about them. The armies of Good and Evil gathered on the fertile plains of Mesopotamia will decide the fate of the world--and the fate of all the future.