Field artillery is a category of mobile artillery used to support armies in the field. These weapons are specialized for mobility, tactical proficiency, long range, short range and extremely long range target engagement.
Until the early 20th century, field artillery were also known as foot artillery, for while the guns were pulled by beasts of burden (often horses), the gun crews would usually march on foot, thus providing fire support mainly to the infantry. This was in contrast to horse artillery, whose emphasis on speed while supporting cavalry units necessitated lighter guns and crews riding on horseback.
Whereas horse artillery has been superseded by self-propelled artillery, field artillery has survived to this day both in name and mission, albeit with motor vehicles towing the guns, carrying the crews and transporting the ammunition. Modern artillery has also advanced to rapidly deployable wheeled and tracked vehicles and precision delivered munitions capable of striking targets at ranges between 15 and 300 kilometers.
Early artillery was unsuited to the battlefield, as the extremely massive pieces could not be moved except in areas that were already controlled by the combatant. Thus, their role was limited to such functions as breaking sieges. Following the beginning of the gunpowder era, the first field artillery came into being as metallurgy allowed thinner cannon barrels to withstand the explosive forces without bursting. However, there was still a serious risk of the constant changes of the battlefield conspiring to leave behind slow-moving artillery units - either on the advance, or more dangerously, in retreat. Artillery units were particularly vulnerable to assault by light cavalry, which were frequently used in this role.
Only with a number of further inventions (such as the limber, hitched to the trail of a wheeled artillery piece equipped with trunnions), did the concept of field artillery really take off. One of the earliest documented uses of field artillery is found in the 14th-century Ming Dynasty treatise Huolongjing. The text describes a Chinese cannon called a "thousand ball thunder cannon," manufactured of bronze and fastened with wheels. The book also describes another mobile form of artillery called a "barbarian attacking cannon" consisting of a cannon attached to a two-wheel carriage.