The Chosen (The Raj Whitehall Series, Book 6)
David Drake is best known for the 'Hammer's Slammers' series which effectively created the subgenre of military SF. S.M. Stirling is the author of the 'Draka' parallel universe series. Together they are the authors of the bestselling 'General' sequence which charts the alternate history of Byzantine hero Belisarius, the finest military genius of his time.