The X Corps of the Grande Armée was the name of a French military formation that existed during the Napoleonic Wars. The corps was first formed in 1807 and placed under the command of Marshal François Joseph Lefebvre. The unit was responsible for bringing the 1807 Siege of Danzig to a successful conclusion. During the French invasion of Russia in 1812, the corps was reconstituted and Marshal Jacques MacDonald appointed to lead it. The corps contained the Prussian contingent that went on to form the core of the reconstituted Prussian army in 1813. After the retreat from Russia, the corps was given the assignment of holding Danzig under the leadership of General of Division Jean Rapp. The 1813 Siege of Danzig lasted from January until November when the garrison surrendered to the Allies.