The United States Army created a large number of notional deception formations that were used in a number of World War II deception operations. The most notable fictional US formation was the First United States Army Group (FUSAG); this force was originally intended as the main invasion force for the Invasion of Normandy. However, the British 21st Army Group took up this role. FUSAG remained in existence on paper and was used during Operation Fortitude South to divert Axis attention to the Pas de Calais area.