The shadow of the lion

"Three writers (the others are Eric Flint and Dave Freer) collaborate on this massive concoction of alternate history, high fantasy, and historical romance set in the sixteenth-century Venice of an alternate world in which Catholicism is factionalized, the Hohenstauffens instead of the Habsburgs rule the Holy Roman Empire, magic works, and the grand duke of Lithuania is trying to use that magic against his enemy, the emperor."--Booklist.