Maximilian I of Mexico

Maximilian was the younger brother of Austria's Emperor Franz Joseph I, a Habsburg who commanded the small Austrian navy and briefly served as viceroy of Lombardy-Venetia before being dismissed. Mexican conservatives, having lost a brutal civil war to the liberals in 1861, sought a European monarch to restore their power with French military backing. Maximilian, a descendant of Charles V who once ruled Mexico as part of the Spanish Empire, seemed ideal - but he misread everything. He accepted the crown on 10 April 1864 after a rigged referendum, pledged French troops at his back, and promptly enacted liberal reforms that alienated the very conservatives who installed him. The United States recognized Benito Juárez as Mexico's legitimate president throughout, and once the American Civil War ended in 1865, Washington began arming the republicans. Napoleon III withdrew French forces in 1866. Maximilian's monarchy collapsed. He was captured in Querétaro, tried, and executed by firing squad alongside two of his generals on 19 June 1867, ending monarchy as a serious force in Mexico.