Historically, cavalry was divided into light and heavy cavalry. The difference was mainly how much armor is worn by the soldiers, and thus how powerful their mounts had to be in order to sustain the burden.

Early light cavalry (like the auxiliaries of the Roman army) was typically used to scout and skirmish and to cut down retreating infantry. Heavy cavalry like the Byzantine Cataphract were used as shock troops, to charge the main body of the enemy and decide the outcome of the battle.

During the Gunpowder Age armored cavalry became obsolescent and the main difference between light and heavy cavalry was their training—either for harassment and reconnaissance or for close-order charges.

Since the development of armored warfare the distinction between light and heavy armor has persisted along broadly the same lines. Armored cars and light tanks have adopted the reconnaissance role while medium and heavy tanks are regarded as the decisive shock troops.

By the Nineteenth Century, European cavalry fell into four main categories:

• Cuirassiers, heavy cavalry
• Dragoons, originally mounted infantry but later regarded as medium cavalry
• Hussars, light cavalry
• Lancers or Uhlans, light cavalry armed with lances

There were cavalry variations for individual nations as well: France had the chasseurs à cheval; Germany had the Jäger zu Pferd; and Russia had Cossacks. Britain had no cuirassiers (other than the Household Cavalry), but had Dragoon Guards regiments which were classed as heavy cavalry. In the United States Army, the cavalry were almost always dragoons. The Imperial Japanese Army had its cavalry dressed as hussars, but fought as dragoons.

Dragoons

A dragoon is a soldier trained to fight on foot, but transport himself on horseback. In other words, they move as cavalry but fight as infantry. The name derives from their primary weapon, a carbine or short musket called the dragon. Sometimes dragon carbines are said to be called as such because they "breathed fire" — a reference to the smoke they emitted when fired.

Dragoons were organized not in squadrons but in companies, like the foot, and their officers and non-commissioned officers bore infantry titles. However, dragoons were at a disadvantage when engaged against true cavalry, and constantly sought to improve their horsemanship and armament to the cavalry standard. Thus, "dragoon" came to mean medium cavalry by the time of the early wars of Frederick the Great, in the 1740's.