Charles William Ferdinand, Duke of Brunswick

Charles William Ferdinand inherited Brunswick-Wolfenbüttel in 1780, a small state in the Holy Roman Empire, and ran it as an enlightened despot - his uncle Frederick the Great had shown him the template. Married to the sister of Britain's George III, he also rose to field marshal in Prussia's army, earning a reputation as one of the century's finest military minds. In 1792 he issued the Brunswick Manifesto, warning revolutionary France that any harm to Louis XVI would bring total vengeance from the allied powers; instead it accelerated the king's fall and radicalized the revolution. By 1806, facing Napoleon at Jena-Auerstedt, the old warfare he'd mastered was obsolete. A musket ball caught him in the battle; he died from the wound a month later, on 10 November.