Nineteenth-century Europe for the most part refused the presence of women in the military, believing that bearing arms was incompatible with femininity, reserving it only for men who possessed the political power from which it was inseparable. Women made their demands in vain, and transgressions of this gender norm were rare. The feminization of the military began in the twentieth century, but initially involved only medical care and auxiliary logistics. The two world wars along with the wars of decolonization amplified the mobilization of women and forced the military in most European countries to establish a lasting legal framework enabling women to become soldiers like anyone else, that is to say like men.
Source : Feminization of European Armies