Infantry support gun

Infantry support guns or battalion guns are artillery weapons designed and used to increase firepower of infantry units they are intrinsic to; offering immediate tactical response to the needs of the unit's commanding officer. The designs are typically with short low velocity barrels, and light construction carriages allowing them to be more easily manoeuvred on the battlefield. They are generally used for direct fire missions, as opposed to indirect fire like other artillery units. Their role has generally been replaced by tanks or other support vehicles, or smaller hand-held weapons.

Infantry support guns were the first type of artillery employed by armed forces, initially in China, and later brought to Europe by the Mongol invasion. In their initial form, they lacked carriages or wheels, and were simple cast barrels called pots de fer in French, or vasi in Italian. These weapons were relatively small, immobile, and fired large bolts or quarrels. Along with increases in the sizes of ordnance (the barrels) came the requirement of easier transportation. This led to two divergent approaches, the very light hand-gun, and eventually the arquebus, while another avenue of development led to the light ordnance, now on wheeled carriages, such as the 2-pounder Culvern moyane, the 1-pounder Falcon, and the 3/4-pounder Falconet. These lighter Renaissance pieces eventually led to the development of the 3-pounder and 4-pounder regimental guns of the 17th century as well as the leather cannon, notably in the army of Gustavus Adolphus. The light field guns of the 17th century, commonly known as a drake in England, came in almost 100 different calibres, with each having its own distinct name, some of which were:

...
Wikipedia