Disclaimer: even if I own several examples of this medal, I wasn’t able to take good shots of them, it was much more simple to take pictures from Wikipedia. Therefore many thanks to Fdutil (Fdutil — Travail personnel. Sous licence CC BY-SA 3.0 via Wikimedia Commons).
This medal was created in 1852 by Napoléon III. Starting from 1870 and until 1940, the Imperial eagle and the head of the Emperor are replaced by more republican symbols, with the 1870 date.
During and after the Great War, 1,400,000 Médailles Militaire were awarded, most of them posthumously. 185,000 medal were awarded during the conflict; 58,000 after the end of the conflict. In 1923, 1,000,000 ca. had been posthumously awarded and 320,255 living veterans had this medal. I’ve published a post a long time ago about the papers linked to this medal.