A Radical Act of Free Magic: H. Parry

The Concord has been broken, and a war of magic engulfs the world.
In France, the brilliant young battle-mage Napoleon Bonaparte and has all but conquered Europe. Britain fights back, protected by the gulf of the channel and powerful fire-magic, but Wilberforce's own battle to bring about free magic and abolition has met a dead end. In Saint Domingue, Fina watches as Toussaint Louverture navigates these opposing forces to liberate the country.
But there is another, even darker war being fought beneath the surface. A blood magician is using the Revolutionary Wars to bring about a return to dark magic. Across the world, only a few know of his existence and the choices they make will shape the new age of magic.