Before the Iron Age, the role of cavalry on the battlefield was largely performed by light chariots. The power of mobility given by mounted units was recognized early on, but was offset by the difficulty of raising large forces and by the inability of horses (then mostly small) to carry heavy armor.

The chariot was first adopted by nomadic or semi-nomadic peoples on the boundaries of civilization in conflicts with civilized peoples. The chariot was quickly adopted by settled peoples both as a military technology and an object of ceremonial status. Pharaoh rides a chariot into battle in the Egyptian New Kingdom, just as the Sun rides a chariot over the sky in Egyptian mythology.

Chariots were quickly superseded by horses when selective breeding resulted in horses able to carry the weight of a fighting man. They retained ceremonial uses, for instance carrying the victorious general in a Roman triumph.

In the armies of the Greeks and Romans it played a relatively minor role—in both civilizations conflicts were decided by massed armored infantry. The cavalry in the Roman Republic remained the preserve of the wealthy landed class—the class eventually dominated by the Roman emperors, who came to power and often succeeded to the throne by virtue of being successful generals of the Roman legions of citizens fighting on foot.

The decline of the Roman infrastructure made it successively more difficult to field large infantry forces, and during the second and third centuries cavalry began to take a more dominant role on the battlefield, also in part made possible by the appearance of new, larger breeds of horses. The replacement of the insubstantial Roman saddle by variants on the Scythian model, with pommel and cantle, was significant too. New armored Cataphracts were deployed in eastern Europe and the near Middle East, notably in Persian forces, as the main striking force of the armies, whereas earlier cavalry had to be consigned to the flanks.

In eastern Europe, Russia, and out onto the Steppes cavalry dominated the battlefield until the early 1600s, because of long distances and better tactics. Huns, Mongols and Cossacks are examples of succeeding horse-mounted peripheral peoples successful in military conflicts with Western civilizations, due to their strategic and tactical mobility.

After defeats, Westerners quickly adopted Eastern cavalry tactics; one of the most famous examples is Gustavus Adolphus of Sweden. As European nation-states became established, they were keen to recruit border peoples to serve in formal roles in national armies. For instance, Cossack cavalry regiments were an important part of the Imperial Russian Army until the Revolution, and some even served in the Red Army.

The introduction of the stirrup allowed for even heavier cavalry. As a greater weight of man and armor could be supported in the saddle, the almost-certainty of being dismounted in combat was reduced, and in the initial charge a lance could be 'set' rather than held over-head—leading to an enormous increase in the impact of a charge. In western Europe there emerged the very heaviest cavalry, the knight—exchanging much of the mobility advantage for a massive, irresistible first charge.

Knights remained a dominant military force in western Europe until the rising population and improved political sophistication revived infantry. Technological changes made infantry more effective, initially highly disciplined pikemen and skilled longbowmen could counter a cavalry charge—if they held their formation and the enemy obliged with a head-long charge. Massed English longbowmen triumphed over French cavalry at Crécy, Poitiers and Agincourt. While at Gisors (1188), Bannockburn (1314), and Laupen (1339), foot-soldiers proved they could stand up to cavalry charges. The Swiss-developed pike square became a key advance in resisting cavalry—although eventually numbers would tell (Battle of St. Jakob an der Birs). The introduction of less effective but simpler missile weapons, like the crossbow, was additionally decisive. A top-quality 15th century army could be 50 percent cavalry, but by the 1520s this proportion had fallen below 25 percent. Knighthood quickly became associated with land ownership and senior positions in the feudal social structure.

From the 1550s, the use of gunpowder weapons solidified infantry's dominance of the battlefield, and began to allow true mass unskilled armies. Arquebusiers and later musketeers, the Spanish tercio and later formations, relegated cavalry to a supporting role—although the pistol was specifically developed to try and bring cavalry back into the conflict, together with manoeuvres such as the caracole.

However, cavalry still had a role to play, even if only to counter other cavalry. Attacking an unbroken infantry force frontally was almost never successful, but the extended linear formations were vulnerable to flank or rear attacks. Cavalry was important at Blenheim (1704), Rossbach (1757), and Friedland (1808), remaining a significant factor throughout the Napoleonic Wars. And while massed infantry was deadly to cavalry it was an excellent target for artillery—and once formations were broken, cavalry was essential and deadly in the harry and rout of the scattered infantry. It was not until individual firearms gained accuracy and improved rates of fire that cavalry was diminished in this role as well.

These forces found new success in Imperial operations (irregular warfare), where modern weapons were lacking and the slow moving infantry-artillery train or fixed fortifications were often ineffective against native insurgents (unless the natives offered a fight on an equal footing, as at Tel-el-Kebir, Omdurman, etc). Cavalry "flying columns" proved effective, or at least cost-effective, in many campaigns—although an astute native commander (like Samori in western Africa, Shamil in the Caucasus, or any of the better Boer commanders) could use the added mobility (but reduced firepower) against European forces.

In the American Civil War regular cavalry was significantly absent, but it continued to play a role as part of screening forces and in foraging and scouting.

In the 20th century the advent of modern vehicles with effective mobility and armor, such as tanks, provided the opportunity for vehicles to replace horses as the key mobile element of an army. This change was made even more necessary by the development of the machine gun and other weapons which could easily destroy cavalry formations. Horses became relegated to logistical roles, with few exceptions (see tachanka).

The demise of cavalry as a decisive force on the battlefield came in the First World War when cavalry forces were slaughtered while failing to achieve a strategic breakthrough on the Western Front. They nevertheless played an important role on several fronts, particularly in the Middle East.

After World War I and the Polish-Bolshevik War, horse cavalry was gradually abandoned as a major combat weapon by the industrialized powers. The last major cavalry battle was the Battle of Komarów in 1920. In the 1920s and '30s most industrialized countries either transformed their cavalry units into mounted infantry or motorized infantry. The last cavalry charges in modern warfare were seen in the Second World War. Although there have been some engagements in twentieth and twenty-first century guerrilla wars involving cavalry, particularly by partisan or guerrilla fighters in areas with poor transport infrastructure, these units were not used as cavalry but rather as mounted infantry.

Famous cavalry forces

• Dragoons
• Uhlans
• Cataphracts
• Hakkapeliitta Finnish cavalry of King Gustav II Adolph of Sweden during the Thirty Years War.
• Hussars
• United States Cavalry
• US 7th Cavalry Regiment
• Katana (Samurai armed with the katana were primarily cavalry)
• Governor General's Horse Guards
• Royal Canadian Mounted Police
• South Alberta Light Horse
• Polish cavalry