Napoleon III used the Mexican intervention to promote a monarchy in Mexico.
Napoleon III ruled the French Second Empire from 1852 until 1870. He supported military intervention in Mexico after the debt crisis of 1861 and continued the campaign even after Britain and Spain withdrew. His government aimed to establish a friendly monarchy and expand French influence in the Americas.
France eventually installed Maximilian of Austria as emperor of Mexico. The project required French troops to sustain it, while republican forces loyal to Benito Juárez resisted across the country. France withdrew its soldiers in 1866 and 1867, leaving Maximilian increasingly isolated.
Napoleon III’s Mexican policy ended in failure. The empire collapsed in 1867, and the French emperor himself was overthrown after France’s defeat in the Franco-Prussian War in 1870. Cinco de Mayo recalls the Mexican victory that challenged his intervention at its outset.