Maximilian I, full name Ferdinand Maximilian Joseph Maria, was the sole monarch of the Second Mexican Empire. Maximilian served as commander of Austrian Navy under his older brother and Emperor of Austria, Franz Joseph I. Napoleon III of France, who sought to legitimize French rule in the Americas by establishing a monarchist ally there, offered Maximilian to rule Mexico. France launched Second French Intervention in Mexico, during which time support from the French army, the Austrian and Belgian crowns and most significantly from a group of conservative Mexican monarchists who wanted to overturn the liberal administration of Mexican president, Benito Juárez, led Maximilian to travel to Mexico where monarchy was declared in July 1863 with Maximilian becoming Emperor Maximilian I of Mexico. While several European powers including Britain recognised the monarchy, the United States still considered Juárez as the legal president of Mexico. Following the American Civil War, the United States aided forces of Juárez and pressurised France to respect the Monroe Doctrine. The French Empire had to withdraw from Mexico following much guerrilla warfare eventually leading to collapse of the monarchy. The Mexicans captured and executed Maximilian and restored the Mexican Republic.