Canon-obusier de 12

"Canon de l’Empereur" Canon obusier de campagne de 12 12-pounder "Napoleon"
Canon obusier de campagne de 12 modèle 1853 on display in Les Invalides.
Type	Regimental artillery field gun
Place of origin	France
Service history
Used by	France, United States, Confederate States of America
Wars	Crimean War, American Civil War
Production history
Designed	1853
No. built	France: ? United States: Union States: 1,100, Confederate states: 600
Specifications
Weight	626 kg (1,227 lb), with carriage: 1,200 kg (2,353 lb)
Length	1.91 m (66 in)
Crew	4
Shell	4.1 kg shell, ball, canister
Caliber	121 mm (4.62 in)
Muzzle velocity	439 m/s (1,440 ft/s)
Effective firing range	1,480 m at 5° elevation (1,440 yd)

The Canon obusier de 12 (French:"Canon obusier de campagne de 12 livres, modèle 1853", USA: 12-pounder Napoleon), also known as the "Canon de l’Empereur" was a type of canon-obusier (literally "Shell-gun cannon", "gun-howitzer") developed by France in 1853. Its performance and versatility (it was able to fire either ball, shell, canister or grapeshot) 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 cannon owes its alias to French president and emperor Napoleon III.

The "canon obusier" was a smoothbore cannon firing either shells, balls, or canister. This was an improvement over previous cannon firing only balls, such as those of the Gribeauval system. The "canon obusier de 12 livres" is commonly described as a "12-pounder" in English, although the nominal rating was based on a slightly different measure - the bore is the size of a solid cast-iron ball weighing 12 livres (old French pounds, about 1.079 English pounds.) As with other cannon rated by nominal weight, the projectile actually used might be of a different weight. The new weapon "revolutionized field artillery. The Napoleon was light enough to be moved rapidly on the battlefield by horses, heavy enough to destroy field fortifications almost a mile away, and versatile enough to fire solid shot, shell, spherical case, and canister." The French Army introduced the "canon obusier de 12" in 1853.

This type of "canon obusier", commonly called in English the "12-pounder Napoleon Model 1857", was the primary cannon used in the American Civil War. Over 1,100 such Napoleons were manufactured by the North, and 600 by the South. At Gettysburg, 142 out of 360 Federal guns (36%) were Napoleons.

The "12-pounder Napoleon" was widely admired because of its safety, reliability, and killing power, especially at close range. It was the last cast bronze gun used by an American army. The Federal version of the Napoleon can be recognized by the flared front end of the barrel, called the muzzle swell. Confederate Napoleons were produced in at least six variations, most of which had straight muzzles, but at least eight cataloged survivors of 133 identified have muzzle swells.