Doubling
On the eve of the First World War, when many European states had adopted the “school of the nation” approach to military recruitment, the transformation of the standing army into a much larger wartime army often involved the “doubling” of peacetime units. During the first few days of mobilization, each peacetime unit would fill gaps in its ranks with younger reservists, men who had completed two or three years of peacetime service in the recent past. At the same time, the peacetime unit would lose a portion of its professional soldiers to a freshly-formed outfit.1 Composed largely of older reservists, this “daughter” unit would bear a close, if not always perfect, resemblance to its “mother.”
Classic examples of this system are provided by the mobilization of elite light infantry units of the French Republic and the German Empire. At the start of the war, each peacetime battalion of chasseurs à pied or Jäger would double itself, thereby creating both a first-line unit and its second-line counterpart. In the German armies, the latter unit bore a name composed of the designation of its peacetime parent and the word Reserve. In the French Army, each second-line unit bore a number calculated by adding forty to the number of its first-line alter ego. Thus, the counterparts of the 14th Jäger Battalion and the 1st Battalion of Chasseurs à Pied were the 14. Reserve Jäger Bataillon and the 41e Bataillon de Chasseurs à Pied.
Because of their dependence upon older reservists, second-line units formed by doubling rarely possessed counterparts of elements that had recently been formed by their parent units. Thus, neither second-line Jäger battalions or second-line battalions of chasseurs à pied possessed the bicycle companies that some of their peacetime antecedents had formed in the past two or three years. Likewise, while most first-line battalions of chasseurs à pied went to war with six rifle companies, their second-line alter egos made do with four rifle companies.
On 1 August 1914 the 1st Battalion of Chasseurs à Pied transferred two captains, one lieutenant, one surgeon, six sergents-fourriers, fourteen sergeants, four corporals, and four ordinary chasseurs to the 41st Battalion of Chasseurs à Pied. Archives de Guerre, JMO 26 N 827/1.