The Pyramids of London. The Trifold Age, #1

In a world where lightning sustained the Roman Empire, and Egypt's vampiric god-kings spread their influence through medicine and good weather, tiny Prytennia's fortunes are rising with the ships which have made her undisputed ruler of the air. But the peace of recent decades is under threat. Rome's automaton-driven wealth is waning along with the New Republic's supply of power crystals, while Sweden uses fear of Rome to add to her Protectorates.
And Prytennia is under attack from the wind itself. Relentless daily attacks destroy crops, buildings, and lives, and neither the weather vampires nor Prytennia's Trifold Goddess have been able to find a way to stop them. With events so grand scouring the horizon, the deaths of Eiliff and Aedric Tenning raise little interest. The official verdict is accident: two careless automaton makers, killed by their own construct.
The Tenning children and Aedric's sister, Arianne, know this cannot be true. Nothing will stop their search for what really happened. Not even if, to follow the first clue, Aunt Arianne must sell herself to a vampire.---Book 1 of a 5 book series.