After Napoleon's defeat at Leipzig in 1813, France itself is now directly threatened by the Allied armies. On December 21st 1813, the Army of Bohemia crossed the Rhine at Basle whilst the Army of Silesia crossed between Coblenz and Mannheim on Janary 1st 1814. The campaign for France is about to being with it's victories and defeats for the French forces.
Meanwhile, a third Allied army makes way towards northern France. Made up of soldiers from Prussia, Russia, Hanover, Saxony and Sweden, the Army of the North has invaded Belgium and is now targetting the Channel ports. Whilst the main thrust of this attack is directed towards Antwerpt, there is a chance that this army may try and take Calais or Boulogne.
In order to reinforce the Channel coast, the ministry of war decided in March 1814 to reorganise the garrisons along this coast. These garrisons will be ordered to watch over these sensitive areas and be ready to help counter a possible advance of the Army of the North. They will also be responsible for the security of supply routes and to train new conscripts.
The 248th Marching Detachement, a provisional unit comprised of drafts from different regiments, holds the citadel of Montreuil-sur-Mer, key forteress town along the French Channel coast to the south of Boulogne-sur-Mer.
The garrison commander
Chasseur of the 10e Régiment d'Infanterie Légère
Infantrymen returning from drill