The decimal military system was the foundation of the Mongol military success. Introduced by Genghis Khan at the kurultai of 1206 and refined by his successors, the decimal system divided the army into units of ten (the arban), a hundred (the zuun), a thousand (the mingghan), and ten thousand (the tümen), each with its own commander and its own identity. The system gave the Mongol army a flexibility and a responsiveness that was unmatched by any of its enemies, and it was one of the keys to the success of the Mongol conquests.
The decimal system 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 system was, in effect, a revolution in military organization, and it has been studied by military commanders for centuries.
The Units of the System
The basic unit of the decimal system was the arban, a unit of ten warriors. The arban was the basic tactical unit of the Mongol army, and the warriors of an arban were expected to fight together, to camp together, and to support each other in the field. The warriors of an arban were typically drawn from a single clan or a single region, and they were bound together by personal loyalty to their commander, called the arbanchi.
The next unit in the system was the zuun, a unit of a hundred warriors. The zuun was composed of ten arbans, and it was commanded by a zuunachi, who was responsible for the conduct of the warriors under his command. The zuunachi was a more senior officer than the arbanchi, and he was typically a member of the Mongol nobility or a trusted follower of the khan.
The next unit was the mingghan, a unit of a thousand warriors. The mingghan was composed of ten zuuns, and it was commanded by a mingghanishi, who was responsible for the conduct of the zuuns under his command. The mingghanishi was a senior officer, and he was typically a member of the imperial family or a trusted adviser of the khan.
The largest unit was the tümen, a unit of ten thousand warriors. The tümen was composed of ten mingghans, and it was commanded by a tümenchin, who was responsible for the conduct of the mingghans under his command. The tümenchin was one of the most senior officers in the Mongol army, and he was typically a member of the imperial family or a close relative of the khan. The tümen was the basic strategic unit of the Mongol army, and it was the unit that was typically deployed on a major campaign.
The Commanders of the System
The commanders of the decimal system were appointed by the khan, and they were responsible to the khan for the conduct of their units. The commanders were chosen for their ability and loyalty, and they were typically promoted on the basis of their performance in the field. The system of appointment was, in effect, a meritocratic system, and it was a major departure from the traditional steppe practice of appointing commanders on the basis of their aristocratic birth.
The most important of the commanders were the tümenchins, who commanded the ten-thousand-man units. The tümenchins were the most senior officers in the Mongol army, and they were typically members of the imperial family or close relatives of the khan. The most famous of the tümenchins was Subutai, the son of a blacksmith, who rose through the ranks to become the most successful general in the history of the Mongol Empire.
The other commanders were also important, and the decimal system gave the khan a large pool of talent to draw on. The system was, in effect, a way of identifying and promoting the most able officers, and it was one of the keys to the success of the Mongol military.
The Imperial Guard (Keshig)
The imperial guard, called the keshig, was a special unit of the decimal system. 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 the training ground for the future commanders of the Mongol army, and 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 Advantages of the Decimal System
The decimal system gave the Mongol army a number of decisive advantages over its enemies. 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 system also made it possible to expand the army quickly. New warriors could be incorporated into the existing units, and new units could be created by promoting existing commanders. The system was, in effect, a way of expanding the army without having to create a new command structure, and it was one of the keys to the rapid expansion of the Mongol army in the thirteenth century.
The Legacy of the Decimal System
The decimal system was one of the most important contributions of the Mongol Empire to the history of military organization. The system was widely copied by the successor states of the Mongol Empire, and it was eventually adopted by the armies of the Ottoman Empire, the Mamluk Sultanate, and the Russian Empire. The system is also significant for its influence on the development of the modern military, which is still organized along broadly decimal lines.
The decimal system is also significant for what it tells us about the political and social organization of the Mongol people. The system was not merely a way of organizing the army; it was a way of organizing society, 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 political and social order.
Sources
- Timothy May, The Mongol Art of War (Barnsley: Pen & Sword, 2007), ch. 2.
- David Morgan, The Mongols (2nd ed., Oxford: Blackwell, 2007), ch. 2.
- 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.
- Christopher I. Beckwith, Empires of the Silk Road (Princeton: Princeton University Press, 2009), ch. 6.
- René Grousset, The Empire of the Steppes: A History of Central Asia (New Brunswick: Rutgers, 1970), ch. 7.