Napoleon begins to consolidate his power in Europe, and within a few years, the continent is embroiled in war. The magical knowledge uncovered by the French naturally leaked out, however. You cannot keep the genie in the bottle once it has been uncorked, after all. Within a few years, every major power had magical research divisions underway, if only scrambling for efforts to counter French magic on the battlefield. The year is now 1812.
War rages on.
Armies and Navies clash, aided by the sorcery of battlefield magicians. With the magical playing field essentially levelled by spies and other information leaks, the Great Powers have now begun looking elsewhere for assistance. Using the d20 rules, all characters in BPCI should be human. Clerics are a special case. All other magic users use the Sorcerer class.