The Exile of Zanzibar by Daniel Maidman

SPFBO9

Claire built a device to fold space and time. It had a flaw...   When the smoke clears, she finds herself halfway across the world, thousands of years in the past, and no device in sight.   In bronze-age Florence, war has lasted for generations. All Claire wants to do is get home, but she'll need help from the locals. She wins an ally in Marcus Diophantus, a pickpocket turned soldier turned general, who hopes to turn into something more than just her champion. Together, they broker peace between Florence and its enemy.   If Marcus is going to help Claire, he'll have to survive. Peace has upset the balance of power in the capital city. The king stands increasingly alone against: the Constantines, a commercial enterprise as much as a clan, who aim to profit from peace as they have from war -- the warrior nobles, descended from the founders of Florence and quick to turn against a weak throne - and Reburrus, the high priest of Florence, convinced Claire answers to hostile foreign gods. As the city comes to a boil, Claire and Marcus - and Marcus's formidable army - will have to decide where their allegiance lies.   Claire becomes a reluctant participant in a savage campaign. While Marcus leads the battles, she tries to gain control of the unimaginably powerful Ctesiphôn - a ghost tower in the heart of Florence, shrouded in magic and myth.