G. A. Henty 
The Young Franc Tireurs 

Historical novel set in the late 19th century, during the Franco-Prussian War. The Preface begins: 'The present story was written and published a few months, only, after the termination of the Franco-German war. At that time the plan–which I have since carried out in The Young Buglers, Cornet of Horse, and In Times of Peril, and which I hope to continue, in further volumes–of giving, under the guise of historical tales, full and accurate accounts of all the leading events of great wars, had not occurred to me. My object was only to represent one phase of the struggle–the action of the bodies of volunteer troops known as franc tireurs.’ According to Wikipedia: 'George Alfred Henty (8 December 1832 – 16 November 1902), referred to as G. A. Henty, was a prolific English novelist, special correspondent, and Imperialist born in Trumpington, Cambridgeshire, England. He is best known for his historical adventure stories that were popular in the late 19th century. His works include Out on the Pampas (1871), The Young Buglers (1880), With Clive in India (1884) and Wulf the Saxon (1895).’