[2] The Mexican expedition was undertaken in 1862 on order of Emperor Napoleon III following a financial dispute with the Republic of Mexico and his personal desire to create a Catholic empire on the continent to counterbalance U.S. influence.

[3] These forces, whose numbers would later rise to approximately 38,000 men, were successively placed under the command of generals Charles de Lorencez, Élie Frédéric Forey and finally François Achille Bazaine.

The campaign was the scene of some of the most notable battles in French military history, such as the glorious struggle for the village of Camaron where, on 30 April 1863, sixty two legionnaires resisted bravely for nine hours against over two thousand Mexicans, allowing for the capture of the city of Puebla on 17 May 1863 thus paving the way to Mexico.

In February 1867, Emperor Napoleon III ordered the repatriation of all remaining French troops from Mexico, the last elements left the port of Vera Cruz on 12 March 1867.

A later decree of 16 April 1864[4] added the Commemorative medal of the Mexico Expedition to the list of previous awards that could be revoked following a condemnation to a fixed prison term of one year or more for a crime committed by the recipient.