The Bréguet XI was a prototype French biplane bomber of the First World War.
In 1915, German fighters and well-established air defense systems made flights by French bombers extremely unsafe. French commanders therefore urgently ordered the production of new, more sophisticated bomber aircraft. Two main lines of development were devised - the development of light, high-speed and heavy, but well-protected aircraft.
The first flight of the Bréguet XI took place in February 1916. Despite the satisfactory test results, the French military refused the aircraft, arguing that the Bréguet XI was too large for frontline aviation.