Noun

cavalry (plural cavalries)

1. (military) The military arm of service that fights while riding horses.
2. (military) Branch of military transported by fast light vehicles, the mechanized cavalry.
3. (military) An individual unit of the cavalry arm of service.

Cavalry (from French cavalerie, cf. cheval 'horse'), were soldiers or warriors who fought mounted on horseback. Cavalry were historically the third oldest (after infantry and chariotry) and the most mobile of the combat arms. A soldier in the cavalry is known by a number of designations such as cavalryman or trooper.

The designation of cavalry was not usually given to any military force that used other animals, such as camels or mules. Infantry who moved on horseback, but dismounted to fight on foot, were known in the 17th and early 18th centuries as dragoons, a class of mounted troops which later evolved into cavalry proper while retaining their historic title.

From earliest times cavalry had the advantage of improved mobility, making it an

"instrument which multiplied the fighting value of even the smallest forces, allowing them to outflank and avoid, to surprise and overpower, to retreat and escape according to the requirements of the moment."

A man fighting from horseback also had the advantages of greater height, speed, and inertial mass over an opponent on foot. Another element of horse mounted warfare is the psychological impact a mounted soldier can inflict on an opponent.

The mobility and shock value of the cavalry was greatly appreciated and exploited in the Ancient and Middle Ages armed forces, and some consisted mostly of the cavalry troops, particularly in nomadic societies of Asia, notably the Mongol armies. In Europe cavalry became increasingly armoured cavalry and eventually became known for the mounted knights. During the 17th century cavalry in Europe lost most of its armour, and by the mid-19th century only some regiments retained the cuirass.

In the period between the World Wars, many cavalry units were converted into motorised infantry and mechanised infantry units, or reformed as tank troops. However some cavalry still served during the Second World War, notably in the Red Army and in the Italian Royal Army. Most cavalry units that are horse-mounted in modern armies serve in purely ceremonial roles, or as mounted infantry in difficult terrain such as mountains or heavily forested areas.