The Three Wars of German Unification

Danish War (1864): Prussia and Austria jointly defeated Denmark and took the duchies of Schleswig and Holstein. Disagreement over the duchies later set up the next war.

Austro-Prussian War (1866): Bismarck engineered a war with Austria over the duchies. Prussia's reformed army crushed the Austrians in seven weeks. Austria was excluded from German affairs, and Prussia organized the North German Confederation under its leadership.

Franco-Prussian War (1870-1871): Bismarck provoked France into declaring war by editing the Ems Dispatch (a diplomatic telegram) to insult French pride. The Prussian army defeated France and captured Napoleon III. The southern German states joined the war on Prussia's side, and after the French defeat they joined the new German Empire. The German Empire was proclaimed at the Hall of Mirrors at Versailles in January 1871, deliberately humiliating France. Germany annexed Alsace-Lorraine from France.