The French Naval Staff had remotely considered converting one of their fast but poorly-protected heavy cruisers into an aircraft carrier, but when spies told of an Italian conversion already underway Duquesne was selected and work began immediately. The result was a fast, poorly protected CV with a large air complement for her size. She carried American Vought Vindicator dive-bombers and French Caudron naval fighters.

When war broke out, Duquesne and her CA sister Tourville were hunting German commerce raiders in the Bay of Bengal. She sided with the Allies when France collapsed and put into Durban for orders. She sailed with a large Allied fleet to sweep the South Atlantic when scouting Vindicators found the Italian CV Sagittario with all her planes fueled, armed, and on deck. The armor-piercing bombs carried by the scouts penetrated deeply but did no damage to the flight deck. Wounded pilot Henri Gaulois, shouting "Revenge for the Strasbourg", earned immortal fame by crashing his burning plane into the parked aircraft, starting an inferno that doomed the CV.

When the Japanese threatened Samoa and other French protectorates, Duquesne left French West Africa and sailed "around the Horn" to the Pacific. In a narrow passage of the Straits of Magellan a Japanese submarine lying in wait fired four torpedoes into the thin hull of Duquesne and tore it apart. There were few survivors in the icy waters.