What was Napoleon's French army called in the Waterloo campaign?

Napoleon’s French army in the Waterloo campaign was called the Army of the North, or L’Armée du Nord in French. It was the force Napoleon assembled and personally led during the Hundred Days of 1815.

The army crossed into the United Kingdom of the Netherlands—modern Belgium—in June 1815, aiming to defeat the allied armies before they could combine. Napoleon attacked the Prussians at Ligny and fought Wellington’s Anglo-allied army at Waterloo. Other French forces remained elsewhere, so the Army of the North referred specifically to the campaign army operating in Belgium.

The name can be confused with Napoleon’s later campaigns or with French armies organized by region, such as the Army of the Alps or Army of Italy. The Army of the North was a wartime field formation, not a permanent national branch. Its senior officers included Napoleon, chief of staff Soult, Marshal Ney and Marshal Grouchy.