It was renamed in 1805 from the army that Napoleon had assembled on the French coast of the English Channel for the proposed invasion of Britain. Napoleon later deployed the army east in order to eliminate the threat of Austria and Russia, which were part of the Third Coalition assembled against France. Thereafter, the name was used for the principal French army deployed in the Campaigns of 1805 and 1807, where it got its prestige, and 1809, 1812, and 1813–14. In practice, however, the term, Grande Armée, is used in English to refer to all of the multinational forces gathered by Napoleon I in his campaigns of the early 19th century (see Napoleonic Wars).
The first Grande Armée consisted of six corps under the command of Napoleon's marshals and senior generals. When Napoleon discovered that Russian and Austrian armies were preparing to invade France in late 1805, the Grande Armée was quickly ordered across the Rhine into Southern Germany, leading to Napoleon's victories at Ulm, Austerlitz and Jena.
The army grew as Napoleon spread his power across Europe. It reached its largest size of 1,000,000 men at the start of the invasion of Russia in 1812, with 680,000 men participating in the Russian campaign. The contingents were commanded by French generals, except for the Polish corps and an Austrian one. The huge multinational army marched slowly east, and the Russians fell back with its approach. After the capture of Smolensk and victory in the Battle of Borodino, Napoleon and a part of the Grande Armée reached Moscow on 14 September 1812. However, the army was already drastically reduced because of deaths and injuries from battles with the Russians, disease (principally typhus), desertion, and long communication lines. The army spent a month in Moscow but was ultimately forced to march back westward. It started to suffer from cold, starvation and disease, and was constantly harassed by Cossacks and Russian irregulars, so that the Grande Armée was utterly destroyed as a fighting force. Only 120,000 men survived to leave Russia (excluding early deserters). Of these, 50,000 were Austrians, Prussians, and other Germans, 20,000 were Poles, and just 35,000 Frenchmen. As many as 380,000 died in the campaign.
Napoleon led a new army to the Battle of the Nations at Leipzig in 1813, in the defence of France in 1814 and in the Waterloo Campaign in 1815, but the Napoleonic French army would never regain the heights of the Grande Armée of June 1812.
For a history of the French army in the period 1792–1804 during the wars of the First and Second Coalitions see French Revolutionary Armies.