Mongol Military Tactics and Warfare

The Mongol army was the most effective military force of the medieval world, and the conquests that it carried out in the thirteenth and fourteenth centuries were among the most remarkable in the history of warfare. From a base of a few hundred thousand warriors on the Mongolian steppe, the Mongols conquered the largest contiguous land empire in the history of the world, a state that stretched from the Pacific to the Carpathians. The army that achieved these conquests was, in many ways, a model of military organization that has been studied by military commanders for centuries.

This page is a complete overview of the Mongol military: its organization, its tactics, its weapons, its logistics, and its strategies. The narrative below is drawn from the Secret History of the Mongols, from the chronicles of Persian historians such as Juvaini and Rashid al-Din, from the testimony of European travelers such as John of Plano Carpini and William of Rubruck, and from the modern scholarship that has reshaped our understanding of the Mongol military in the last fifty years.

The Foundation: The Decimal Army

The foundation of the Mongol military success was the decimal organization that Genghis Khan introduced at the kurultai of 1206. Genghis Khan divided his followers into units of ten (the arban), a hundred (the zuun), a thousand (the mingghan), and ten thousand (the tümen), and appointed his own commanders to each unit. The decimal organization was not merely a way of counting soldiers; it was a way of organizing society, a way of building loyalty, and a way of ensuring that the army could be deployed with maximum flexibility.

The decimal organization gave the Mongol army a number of decisive advantages. The first was flexibility: the units could be combined and recombined in a wide variety of ways, and the army could be tailored to the specific needs of any given campaign. The second was loyalty: the warriors owed personal loyalty to their immediate commanders, and the commanders owed personal loyalty to the khan. The third was discipline: the units were responsible for the conduct of their members, and the commanders were responsible for the conduct of their units.

The decimal organization was also a social revolution. The warriors were no longer identified by their tribal affiliation, but by their unit of service. The unit became the primary social group, and the loyalty of the warrior to his unitmates was more important than his loyalty to his clan. The change was, in effect, a revolution against the old aristocratic lineages, and it was the foundation of the Mongol military tradition.

The Imperial Guard (Keshig)

The second key institution of the Mongol military was the imperial guard, called the keshig. The keshig was a body of ten thousand men, drawn from the most loyal and able of Genghis Khan’s followers, who served as the personal guard of the khan. The keshig was quartered at the imperial court and served as the training ground for the future commanders of the Mongol army; many of the most famous Mongol generals, including Subutai and Jebe, served in the keshig before being given field commands.

The keshig was also the center of the imperial administration. It was the keshig that kept the imperial records, communicated the khan’s orders, and served as the first line of defense against rebellion and assassination. The keshig was, in effect, the imperial headquarters, and it was the model for the imperial guards of the khanates that would follow.

The Horse Archers

The third key element of the Mongol military was the horse archer. The horse archer was the basic tactical unit of the Mongol army, and the use of mounted archers gave the Mongols a decisive advantage over most of their enemies. The horse archer was equipped with a recurved composite bow, a short sword, a lance, and a lasso, and he was trained to shoot accurately from horseback at a full gallop.

The horse archer was the central feature of Mongol military tactics, and the Mongol horse was, in effect, a second weapon. The Mongol horse was a small, hardy breed that was capable of sustained travel and that could survive on minimal food and water. The Mongols used multiple horses for each warrior — typically three or four — and the system of remounts allowed the Mongol army to travel and fight at speeds that were unmatched by any of their enemies.

The Battle Tactics

The battle tactics of the Mongol army were among the most sophisticated in the medieval world. The Mongols used a wide variety of tactics, including the feigned retreat, in which the Mongols pretended to flee, drawing the enemy into a pursuit, and then turned and counterattacked; the envelopment, in which the Mongols surrounded the enemy army and attacked from multiple directions; the hammer and anvil, in which one part of the army engaged the enemy while another part attacked from a different direction; and the use of scouts and intelligence to identify the weaknesses of the enemy.

The Mongols also used a sophisticated system of signals and communication on the battlefield, including flags, banners, and drums. The system allowed the Mongol commanders to coordinate the actions of different units, and it allowed the army to respond quickly to changing circumstances. The system was, in effect, a precursor of the modern system of military communication, and it was one of the keys to the success of the Mongol army.

The Siege Warfare

The siege warfare of the Mongols was another key element of their military success. The Mongols were not, at the beginning of their conquests, expert at siege warfare, but they quickly learned the art from the Chinese and the Muslims. The Mongols recruited engineers and craftsmen from the conquered peoples, and they used a wide variety of siege weapons, including catapults, ballistas, and (after the conquest of the Song Dynasty) gunpowder weapons.

The most famous of the Mongol siege weapons was the trebuchet, a large counterweight catapult that could hurl heavy stones at the walls of a besieged city. The Mongols also used a wide variety of other siege weapons, including battering rams, siege towers, and (most famously) gunpowder weapons such as fire lances, bombs, and rockets. The use of gunpowder weapons was a major innovation of the Mongol military, and it was one of the ways in which the Mongols helped to spread military technology across Eurasia.

The Yam Postal System

The yam postal system was a key element of the Mongol military infrastructure. The yam was a network of way stations, located at intervals of roughly twenty-five to thirty miles, where riders on imperial business could find fresh horses, lodging, and food. The yam was originally designed for military and administrative purposes, but it was also made available to merchants and other travelers who carried the appropriate imperial passport.

The yam was a major factor in the success of the Mongol military. The system allowed the Mongol commanders to communicate with the central government in a matter of days, and it allowed the government to send orders and reinforcements to the front in a matter of weeks. The system also allowed the government to gather intelligence from the far ends of the empire, and it allowed the merchants to supply the army with goods and materials.

The Weapons and Armor

The weapons and armor of the Mongol warriors were standardized and effective. The basic weapon of the warrior was the recurved composite bow, a small but powerful bow that could shoot accurately at distances of up to 200 meters. The bow was made of layers of wood, horn, and sinew, glued together and wrapped in birch bark. The bow was held in a leather case when not in use, and the warrior carried a quiver of arrows, with three different types of arrows for different purposes.

The warrior also carried a short sword, a lance, and a lasso. The short sword was a single-handed weapon used for close combat; the lance was a long pole weapon used for thrusting; the lasso was a rope used for capturing horses and enemies. The warrior wore a set of leather armor, which was light enough to allow mobility but heavy enough to provide some protection against arrows and swords.

The Logistics

The logistics of the Mongol army were among the most impressive in the medieval world. The army could travel light, living off the land and the herds in many cases, and it could remain in the field for months at a time. The army was supported by a train of supply wagons — light, four-wheeled carts, two per warrior in the standard tümen — that carried dried meat (borts), aaruul (dried curds), millet, and spare arrows. The army was also supported by a corps of scouts and messengers (achi / elchi) that gathered intelligence and reported on the movements of the enemy.

The logistics of the Mongol army were made possible by the discipline of the warriors and by the Yassa code of law, which required every warrior to maintain a certain number of horses and a certain amount of equipment, on pain of death. The logistics were also made possible by the system of supply depots — established at strategic points along the trade routes — that could be used to resupply the army in the field.

The Strategy

The strategy of the Mongol army was based on a number of key principles. The first was the concentration of force at the decisive point. The Mongols preferred to engage the enemy with a smaller force, and they used their superior mobility to choose the time and place of the engagement. The second was the use of intelligence. The Mongols used spies, scouts, and informants to gather information on the enemy, and they used this information to plan their campaigns and to identify the weaknesses of the enemy. The third was the use of terror. The Mongols used terror as a weapon, and they deliberately spread stories of the destruction of cities that had resisted them in order to encourage other cities to surrender.

The Mongols also used a sophisticated system of alliances, and they were often able to convince their enemies to surrender or to switch sides. The Mongols offered generous terms to cities that surrendered, and they often incorporated the defeated warriors into their own armies. The system of alliances was, in effect, a way of expanding the army without having to recruit and train new warriors, and it was one of the keys to the success of the Mongol military.

The Legacy of the Mongol Military

The Mongol military has had a lasting impact on the history of warfare. The decimal organization, the use of horse archers, the siege warfare, the postal system, and the use of psychological warfare were all major innovations of the Mongol military, and they have been studied by military commanders for centuries. The Mongol military is also significant for the role it played in the spread of military technology across Eurasia, including the spread of gunpowder weapons from China to the Middle East and Europe.

The legacy of the Mongol military is also visible in the modern world. The decimal organization of the army, the use of combined arms, the emphasis on intelligence and logistics, and the use of terror as a weapon are all features of the modern military that can be traced, in part, to the Mongol military tradition. The Mongol military is, in this sense, a major contribution to the history of warfare, and it is one of the most important military traditions in the history of the world.

Sources

Timothy May, The Mongol Art of War: Genghis Khan to the Mamluks (Barnsley: Pen & Sword, 2007) — the best single treatment of the Mongol military system in English.
David Morgan, The Mongols (2nd ed., Oxford: Blackwell, 2007), ch. 2.
Christopher I. Beckwith, Empires of the Silk Road: A History of Central Eurasia from the Bronze Age to the Present (Princeton: Princeton University Press, 2009), ch. 6.
John Man, Genghis Khan: Life, Death and Legacy (London: HarperCollins, 2004), ch. 8.
Paul Ratchnevsky, Genghis Khan: His Life and Legacy (Oxford: Blackwell, 1991), ch. 7.
René Grousset, The Empire of the Steppes: A History of Central Asia (New Brunswick: Rutgers, 1970; trans. Naomi Walford from the 1939 French original), ch. 7.
Stephen R. Turnbull, Mongol Warrior 1200–1350 (Oxford: Osprey, 2003) — for the practical material culture of the Mongol warrior.

Mongol Military Tactics and Warfare — The Army That Conquered Eurasia