This Carte de Visite is the earliest photographic representation of a member of the famed Légion Étrangere - the Foreign Legion - that I have ever come across.
It shows Sous Lieutenant De la Salle who also served as a Maréchal de Logis (sergeant) in the Chasseurs D'Afrique. De la Salle served with the Legion in Mexico during Napoleon III's attempt to turn that county into a French colony.
This Carte de Visite is a copy of an earlier photograph although based upon the thinness of the card mount the copy itself must date from the 1860's or very soon after France's incursion into Mexico. One wonders if De la Salle survived his posting to Mexico - the graveyard of French Colonial aspirations in North America.
Many thanks to Troy Thompson for helping with the translation of the photograph's inscription.
Carte de Visite