Despite being relatively few in number (approximately 200,000 people at the height of their empire), the Mongols played an important part in early world history. Rising initially under the leadership of Genghis Khan, the Mongols created the largest land empire in world history, encompassing 13.8 million square miles and more than 100 million people under their rule. At their height, they controlled most of China, Korea, Afghanistan, Georgia, Armenia, Russia, and Hungary, and all lands in between.
The Mongols were a nomadic people who in the 13th century found themselves encompassed by large, city-dwelling agrarian civilizations. However, none of these civilizations were part of a strong central state. Asia, Russia, and the Middle East were either declining kingdoms, or composed of city states. Taking the strategic initiative, the Mongols exploited this power vacuum and linked all of these areas into a mutually supporting trade network. The Mongols were completely dependent on trade with the city dwelling peoples. As nomads, they could not accumulate a surplus to tide themselves over during bad times, or support artisans to produce technological goods. The beginning of conquest, in 1200, was due to the fact that the kingdom that controlled northern China reduced trade with the Mongols. They attacked to survive.
Conquering, in the Khan's initial viewpoint, did not consist of subordination of competing cultures to the nomadic way of life, but rather in their destruction. As a nomad, Genghis Khan is supposed to not have understood (or cared) of the supposed benefits in the city dwellers way of life. This is in sharp contrast to the obvious reality of their dependence on trade with these people, however the economic theories to explain these relationships still lay seven centuries in the future. The Khan's initial plan was said to have consisted of destroying conquered opponents territory, destroying all traces of their civilization, and converting the lands to pasture for his herds. However, Sorghaghtani Beki (see Philosophy of Empire, below) pointed out a previously unseen advantage to keeping the status quo. If the city dwelling peoples were allowed to continue their way of life (strange as it may have seemed to the Khan), they could produce a surplus of food and goods, a portion of which could be paid to the Khan as taxes. Given the Khan's extraordinary success in his aggressive foreign policy, this wealth could be equally extraordinary. After some thought, the Khan agreed, taking his tribute in tax, and saving countless lives and cultures in the process.
Genghis Khan in particular, never had any intention of creating a world empire. Each of his conquests was started by a specific dispute over the developing trade network (the treatment of Mongols or Mongol merchants, or disadvantageous terms for trade). One such example is the capture of Yanjing[?] (literally, the north capital, in Chinese) in 1215. He refused to exploit the capture of the capital of all of northern China, a real prize. After his success, he simply returned home to the steppe. The same pattern was repeated throughout the conquest of Western Asia, taken at a breakneck pace over only 6 years. It was a simple formula, conquer the resistance, establish advantageous trade terms, and return. The hidden benefit of this reluctance was to avoid the trap that all civilizations have made in trying to create a large empire on purpose. Simply put, rapid expansion leads to overextension of the empire, and the inability to support outlying districts from invasion. Ancient Rome is a prime example of this problem.
The western expansion was a success for the empire until 1242. As they encountered the peoples of Europe, the Mongols with their advanced way of warfare were unstoppable. The Mongols used (and by doing so, introduced) several revolutionary military ideas to European combatants, their most serious opponents by the end of their period of expansion.
The most famous Mongol in the 13th century (much more so than Genghis Khan himself) was Kublai Khan's mother, and Genghis Khan's daughter-in-law, Sorghaghtani Beki[?]. She is mentioned by numerous and far flung contemporary 13th century writers, such as the Persians, European missionaries, and Arab scholars as the most renowned of all Mongols. A Middle Eastern physician commented, "if I were to see among the race of women another who is so remarkable a woman as this, I would say that the race of women is superior to the race of men", quite a complement from a individual in a culture well known for its misogynistic view of women in the 13th century.
Beki's greatest single feat was to recognize the serious problems the Mongols would encounter in running a transcontinental empire. Although illiterate herself, as she groomed each of her four sons (all to become Khans) for rule, she made certain each would learn a different foreign language used in ruling their subject peoples. In addition, she educated court retainers and nobles in the religions of each subject people and sent them to become members of the clergy in each region. Religious tolerance was mandated by law, (unheard of in the ancient world, and many areas of the world today), and all religions were equally supported throughout the empire. This eliminated a source of conflict around which resistance to Mongol rule could be based.
Her greatest contribution to Mongol rule was that she recognized that pure economic exploitation of subject peoples would be counterproductive. Thus, instead of remaking China into a Mongol pasture, she supported existing Chinese society. The increased production realized by enlightened Mongol rule would lead to increased tax and tribute. Each of her sons followed the same philosophy, ensuring continuity and stability. Tolerance, religious and economic support, and literacy were the innovations that took a small nomad people to rulers of all they surveyed.
The Mongols attempted two unsuccessful invasions of Japan. The first invasion fleet was utterly destroyed by a typhoon (kamikaze). The Mongolian fleets survived the typhoon the second time but the landed troops, starved because their provisions had been lost in the typhoon, were annihilated by Japanese infantry and samurai.