Introduction
Even without the text written at the back of this photograph, it is obvious that this soldier is very young.
Despite that he was already decorated with the Croix de Guerre.
He is also wearing the ribbons of two other decorations.
The vertical stripped one could be the “Médaille commémorative française de la grande guerre”.
This would indicate that picture had been taken after the 23th of June 1920 when this decoration was created.
To which decoration the other ribbon belongs is not clear to me.
The double fourragère on his left shoulder, together with the regimental number 1 on the collar patches indicates he served in the French Foreign Legion.
Not uncommon for soldiers of the Legion in that period is that he is wearing a kepi with a half moon crescent instead of the grenade with seven flammes.
The half moon crescent refers to the fact that the RMLE was part of the Division Marocaine.
Notable is the fact that our young soldier forgot either the close one of uniform buttons or that this one was missing.

Who was this young legionnaire ?
The photograph I obtained via the auction site Delcampe.
It came without further provenance.
Any chance identifying this soldier therefore depends on the text written at the back.
Unfortunately, certain sections are difficult to read.
Any assistance would be welcome.
Following my transcript

Geneve [?] le 28/7/20
Offert a Mm Garnie en souvenir d’un ancien éléve engagé dans la Legion Etranger décoré a 18 ans com. volontaire Suisse.
Ex Sergent Louis Gruffat
1er Etranger
26 compagnie montee
Sidi-Bel-Abbes
par Oran
Algérie
Most likely the name of the legionnaire was Louis GRUFFAT.
Further research on this name however sofar did not yield any further information.

Képi Troupe, en drap bleu horizon