Someohow or other I picked this up electronically under the impression that it was the first in a series, and I could read it and decide if I liked the others. In fact it's the third in a series of alternative history novels where the sixth century AD Byzantine general Belisarius, with computer sidekick, battles against an Indian dynasty who have been supplied with gunpowder by allies from the far future.
I won't bother with the rest. Belisarius and his entourage were all fascinating personalities, but this is fan-fiction about them at six-volume length. They never lose a battle or an argument, and have all the best lines to the point that you wish their enemies would hire new speechwriters. It's also not clear what the ultimte aim of Belisarius' time-travelling backers is - they can hardly turn history back into the proper channel after clearing up the Malwa menace (as Belisarius does with the river Euphrates in this book). Pleasant enough reading, but not really compelling.