Some french guy
Apparently it was probably the German guy rather than the French guy.
https://quoteinvestigator.com/2017/10/15/army/
An Army Marches On Its Stomach
This saying has been ascribed to the famous leaders Napoleon Bonaparte and Frederick the Great. Would you please explore this topic?
Quote Investigator: The earliest strong match known to QI appeared in the 1858 work “History of Friedrich the Second, Called Frederick the Great” by the prominent philosopher, essayist, and historian Thomas Carlyle.
They were stronger than Turk and Saracen, but not than Hunger and Disease. Leaders did not know then, as our little Friend at Berlin came to know, that “an Army, like a serpent, goes upon its belly.”
The referent “little Friend at Berlin” was ambiguous, but a later volume of this work by Carlyle clearly ascribed the adage to Frederick II, i.e., Frederick the Great.
Napoleon did make thematically related remarks that were reported (in translation) in the 1824 book “Journal of the Private Life and Conversations of the Emperor Napoleon at Saint Helena” by Count de Las Cases.
There is good evidence that Napoleon made a related general remark: “It is hunger that makes the world move.” He also said of the military that “There is no subordination with empty stomachs”. These comments appeared circa 1816 in “Journal of the Private Life and Conversations of the Emperor Napoleon at Saint Helena”.
However, it says that we don't have anything prior to Carlyle's attribution to Frederick the Great, and Frederick died some decades before that, so it's possible that Carlyle is in error.
