cavalry,military forcemounted onhorseback, formerly an important element in the armies of allmajor powers. When employed as part of a combined military formation, its main duties included observing and reporting information about the enemy, screening movements of its own force, pursuing and demoralizing a defeated enemy, maintaining a constant threat to an enemy’s rear area, striking suddenly at detected weak points, turning exposed flanks, and exploiting a penetration or breakthrough.

During the latter part of the 19th century, largely as a result of the introduction of repeating rifles and machine guns, the cavalry lost much of its former value. By the time ofWorld War I, a cavalry charge against entrenched troops armed with rapid-firing small arms was suicidal. Cavalry organizations soon abandoned horses for armoured fighting vehicles and became known as mechanized cavalry orarmoured cavalry. By the 1950s there were no horse-mounted cavalry units in either the U.S. or British armies. In the early 1960s theUnited Statesconverted its 1st Cavalry Division to an “air mobile”division, with helicopters and air-portable weapons and vehicles. The division saw extensive service inVietnam.