My great-grandfather Jean SERVAT was conscripted into the French Army on March 5, 1915, at age 43, and was discharged May 22, 1917, returning to his hometown of Erce, Ariege. I have his "number," 599, but I don't know if that is a unit number or his identification number in the defense department. Is there any way to find out where he fought? The only other information I have is "Campaigne de Allemagne" but when I Google that term all I get is references to Napoleon.

Are French military records online? It's easy to find ancestors who died in the Great War but I'm interested in where the men from Erce went for the two years they served.