It was formed to fight against Napoleon as part of the Imperial Russian army but was paid by Russia's ally, Great Britain. Ernst Moritz Arndt, the private secretary to the pro-Russian Heinrich Friedrich Karl vom und zum Stein, acted as head propagandist to entrants to the Legion. He stayed in Saint Petersburg from 1812 onwards and attracted entrants by winning them over to fight to liberate Germany from its French occupying forces.
The Russian–German Legion was 9,379 strong in total and consisted of eight infantry battalions, one company of Jägers, two regiments of hussars and two batteries of horse artillery.
Carl von Clausewitz was among notable soldiers of the Legion.
On 6 July 1812, after the contract of Peterswaldau, Great Britain received the task of providing for the Russian–German Legion and thus acquired the right to determine how and where it was to be deployed. Ludwig von Wallmoden-Gimborn was now put in command, and the Legion ventured to the lower Elbe, fought at Mecklenburg and Holstein, attacked Harburg and marched far as the Netherlands. In mid March 1814 it crossed the Rhine and fought in Flanders in order to blockade Antwerp.
After returning from France in 1814, the Legion was received by Prussia, where collaborators were viewed critically, and so on 2 June 1814 it was renamed the German Legion. The Legion moved to Kurhessen for exercises in 1814 and from then until 1815 took up quarters in the Bergischen.
After Napoleon's return from Elba on 26 February 1815, the soldiers of this unit were merged into the 30th and 31st infantry regiment, 8th (Russisch-Deutsche Legion) Ulanenregiment and 18th and 19th horse-artillery batteries of the Prussian army. These units took part in the Waterloo campaign, known as the Hundred Days, as part of the III Corps of the Prussian Army.
- Karl Schröder: Eitorf unter den Preußen, Heimatverein Eitorf 2002, ISBN 3-87710-321-9
- Helmert/Usczek: Europäische Befreiungskriege 1808 bis 1814/15, Berlin 1986