Horse artillery was a type of light, fast-moving, and fast-firing artillery which provided highly mobile fire support, especially to cavalry units. Horse artillery units existed in armies in Europe, the Americas, and Asia, from the early 17th to the mid-20th century. A precursor of modern self-propelled artillery, it consisted of light cannons or howitzers attached to light but sturdy two-wheeled carriages called caissons or limbers, with the individual crewmen riding on horses. This was in contrast to the rest of the field artillery, which were also horse-drawn but whose gunners were normally transported seated on the gun carriage, wagons or limbers. Tactics Once in position, horse artillery crews were trained to quickly dismount, deploy or unlimber their guns (detach them from their caissons), then rapidly fire grapeshot, shells or round shot at the enemy. They could then just as rapidly limber-up (reattach the guns to the caissons), remount, and be ready to move to a new position, similar to the shoot-and-scoot tactics of their modern counterparts. Horse artillery was highly versatile and often supported friendly cavalry units by disrupting enemy infantry formations such as infantry squares with rapid concentrated fire. This would leave the enemy infantry vulnerable to cavalry charges. Their mobility also enabled them to outmaneuver enemy foot artillery units, and to act as a rearguard (in concert with friendly cavalry) to cover the retreat of slower units. A full battery could have a combined front of riders over 50 men strong. If the horse artillery was mistaken for cavalry, the enemy might receive an unpleasant surprise when the towed batteries wheeled around, unlimbered, loaded, sighted and opened fire. Highly proficient batteries could do so in less than a minute. History Origins Essentially a hybrid of cavalry and artillery, irregular horse artillery units were first used by Sweden in the 17th century during the Thirty Years' War by Lennart Torstenson. Torstenson was the artillery expert of Gustavus Adolphus, and used them to provide cavalry with the fire support it needed to deal with massed infantry formations without sacrificing their speed and mobility. Gustavus Adolphus had previously tried intermixing infantry units with cavalry, and this was somewhat successful since the cavalry at that time did not charge the enemy at full gallop. Others tried to combine firepower with mobility by using novel cavalry tactics such as the caracole, but these slowed the cavalry down and proved largely ineffective. The best