By the mid-second millennium B.C., the use of horses in warfare had become common throughout the Near East and Egypt. This development was made possible by advances both in the design of chariots, in particular the invention of the spoked wheel, which replaced the solid wooden wheel and reduced a chariot’s weight, and the introduction of all-metal bits, which gave chariot drivers more control over their horses. Though chariot warfare was expensive, and its effectiveness was determined by the durability of the chariots and suitability of the terrain, the vehicles became essential battlefield equipment. According to archaeologist Brian Fagan of the University of California, Santa Barbara, Bronze Age chariots acted largely as mobile archery platforms, with the bulkier four-wheeled ones also being used to carry kings into battle or to allow generals to observe the fighting. Lighter two-wheeled versions, such as those found in Tutankhamun’s tomb, were better suited to carrying a single archer and a driver.

One of the most informative sources for the use of chariot horses in the ancient Near East is a tablet discovered in 1906–1907 in the royal archive at the Hittite site of Hattusa in Anatolia. The “Kikkuli Text,” written in cuneiform script and dating to around 1400 B.C., is named after its author. Kikkuli introduces himself in the first line as a “horse trainer from the land of the Mitanni,” a state in what is now northern Syria and southeastern Turkey. He then describes an approximately 184-day training cycle that begins in the fall, in which he includes instructions for the horses’ feeding, watering, and care, recommending stable rest, massages, and blankets.

For nearly a millennium, warhorses were used almost exclusively to pull chariots, but after about 850 B.C. chariotry began to decline. Horses, however, never lost their usefulness in battle. Within about 150 years, cavalry, which is suitable to almost any terrain, virtually replaced chariotry in the Near East, and, eventually, horse-drawn chariots were employed primarily for racing, in ceremonial parades, and as prestige vehicles. In time this happened not only in this region, but across most of Europe as well. The rise of true cavalry was the determining force behind many of the major events that influenced European history, including Charles Martel’s defeat of the Saracens at the Battle of Poitiers in A.D. 732, the creation of the Holy Roman Empire, and the victory of William the Conqueror at the Battle of Hastings in A.D. 1066. “I think that the most important development in history with respect to animals was the adoption of the horse as a weapon of war,” says Fagan.

Once horses were domesticated, they began to play an important role in funeral rituals. Archaeologists have found horse bones mingled with cow and sheep remains in human burials on the Eurasian steppe dating to as early as 5000 B.C. All the animals were probably sacrificed and eaten during funeral rituals. Later, the increasingly singular role horses played in human lives was reflected in more elaborate burial rites that were practiced by unrelated cultures from China to England. Perhaps the first to accord horses an honored role in burials were the Sintashta people, a sedentary culture that built large fortified settlements south of the Ural Mountains around 2000 B.C. Important members of this society were buried with their chariots and the horses that pulled them. Unlike other livestock that may have been sacrificed and eaten during funeral rites, these horses went with their owners to the afterlife intact.

Many steppe cultures that came after the Sintashta also practiced horse burials. In Siberia, the fifth-century B.C. Iron Age Pazyrk people buried their noble dead in huge mounds, accompanied by horses outfitted with cloth saddles and dramatic headdresses. But it was in China that horse burials achieved their most elaborate expression. Excavation of the sixth-century B.C. tomb of Chinese ruler Duke Jing of Qi has revealed the remains of 200 horses, which would have represented a vast fortune. The tomb has not been fully excavated, and some archaeologists estimate it might have held up to 600 horses. This number is only rivaled by representations of horses accompanying the terracotta army discovered in pits near the famed mausoleum of China’s first emperor, Qin Shihuangdi (r. 220–210 B.C.). Archaeologists estimate that 130 chariots were buried there, along with bronze and terracotta depictions of more than 650 horses.

In the Greco-Roman world, racehorses were potent symbols used by both individuals and the state to express power, encourage civic pride, and celebrate special events. For the Greeks, chariot racing likely began sometime around 1500 B.C. and became a central element of their most sacred festivals. A memory of these early contests appears in Homer’s description of the funeral games honoring the fallen warrior Patroclus, during which Greek kings and heroes race once around a tree stump for the prize of a female slave. Perhaps a century after the founding of the Olympics in 776 B.C., chariot and jockeyed races were included in the games. This provided an opportunity for families to display their “hippic”—or horse—wealth as social and political capital, explains historian Donald Kyle of the University of Texas at Arlington.

Yet for the Romans, hippic contests were just as often part of extravagant state-sponsored displays intended to entertain the masses. The historian Livy says that the first and largest Roman hippodrome, the Circus Maximus, was built by Lucius Tarquinius Priscus, the legendary fifth king of Rome (r. 616–579 B.C.), in a valley between the Aventine and Palatine hills. Though originally a simple open oval space similar to a Greek hippodrome, the Romans gradually created a massive stadium-style building that, by the first century A.D., could accommodate perhaps as many as 250,000 spectators. While there were certainly other crowd-pleasing events such as gladiatorial contests in ancient Rome, “chariot racing is the earliest and longest-enduring major spectacle in Roman history,” says Kyle.