The Canon obusier de 12, also known as the "Canon de l’Empereur", was a type of canon-obusier developed by France in 1853. Its performance and versatility allowed it to replace all the previous field guns, especially the Canon de 8 and the Canon de 12 as well as the two howitzers of the Valée system.

The M1857 12-pounder Napoleon or Light 12-pounder gun or 12-pounder gun-howitzer was a bronze smoothbore muzzle-loading artillery piece that was adopted by the United States Army in 1857 and extensively employed in the American Civil War. The gun was the American-manufactured version of the French canon obusier de 12 which combined the functions of both field gun and howitzer. The weapon proved to be simple to produce, reliable, and robust. It fired a 12.03 lb (5.5 kg) round shot a distance of 1,619 to 1,680 yd at 5° elevation. It could also fire canister shot, common shell, and spherical case shot. The 12-pounder Napoleon outclassed and soon replaced the M1841 6-pounder field gun and the M1841 12-pounder howitzer in the U.S. Army, while replacement of these older weapons was slower in the Confederate States Army. A total of 1,157 were produced for the U.S. Army, all but a few in the period 1861–1863. The Confederate States of America utilized captured U.S. 12-pounder Napoleons and also manufactured about 500 during the war. The weapon was named after Napoleon III of France, who helped develop the weapon.