While the tune was composed prior to the Legion's departure for Mexico in the 1860s, the lyrics were progressively composed after the Franco-Prussian War since Alsatians and Lorrains flocked to the legion after the regions were annexed by Germany. The song makes also repeated reference to the fact that the Belgians are "lazy shirkers", which comes from the fact that Belgian King Leopold II, who wished to remain neutral in the Franco-German conflict, asked the French government not to commit the Belgian Legionnaires into the conflict. France agreed, and the Belgian Legionnaires remained in French Algeria, the Legion's home, to the dismay of the rest of the Legionnaires. The song thus says that there is no blood sausage ("boudin") for the Belgians. The song also mentions the Swiss who constituted the most important foreign contingent of the Legion in the 1870s.