The foundations of the Pax Mongolica lie in the germinal Mongol Empire beginning with Genghis Khan in the early 13th century. In the process of conquering the various tribes in the region, Genghis Khan revolutionized the way Mongolian tribal society was structured. After each new victory, more and more people were incorporated under Genghis Khan's rule, thus diversifying the societal balance of the tribe. In 1203, Genghis Khan, in an effort to strengthen his army, ordered a reform that reorganized his army's structure while breaking down the traditional clan- and kindred-based divisions that had previously fragmented the society and military. He arranged his army into arbans (inter-ethnic groups of ten), and the members of an arban were commanded to be loyal to one-another regardless of ethnic origin. Ten arbans made a zuun, or a company; ten zuuns made a myangan, or a battalion; and ten myangans formed a tumen, or an army of 10,000. This decimal system organization of Genghis Khan's strong military would prove very effective in conquering, by persuasion or force, the many tribes of the central Asian steppe, but it would also strengthen Mongol society as a whole. By 1206 Genghis Khan's military expansion had unified the tribes of Mongolia, and in the same year he was elected and acclaimed as the leader of Mongolia.
The new Mongol Nation quickly moved to annex more territory. The first Mongol conquests were campaigns against the Xi Xia Empire in western China. In 1209 the Mongols conquered the Xi Xia. Between 1213 and 1214 the Mongols conquered the Jin Empire, and by 1214 the Mongols had captured most of the land north of the Yellow River. In 1221 Mongol generals Jebe and Subodei began their expedition around the Caspian Sea and into Russia; Genghis Khan defeated Persian Jalal ad-Din Mingburnu at the Battle of Indus and the war with the Khwarezmian Empire concluded the same year. In 1235 the Mongols invaded Korea. Two years later in 1237 Batu Khan and Subodei began their conquest of Russia, they conquered Poland and Hungary in 1241. In 1252 the Mongols began their invasion of Southern China; they would seize the capital of Hangzhou in 1276. In 1258 Hulagu Khan captured Baghdad.
Each new victory gave the Mongols the chance to incorporate new peoples, especially foreign engineers and laborers, into their society. Each new conquest also acquired new trade routes and the opportunity to control taxation and tribute. Thus, through territorial expansion, the Mongol Nation not only became an empire, but it also became more technologically and economically advanced.
 Trade network
At its height, the Mongolian empire stretched from Shanhaiguan in the east to Budapest in the west, from Russia in the north to Tibet in the south. This meant that an extremely large part of the continent was united under one political authority. As a result, the trade routes used by merchants became safe for travel, resulting in an overall growth and expansion of trade from China in the east to Britain in the west. Thus, the Pax Mongolica greatly influenced many civilizations in Eurasia during the 13th and 14th centuries.
 World trade systemThe Silk Road was a system of trade routes connecting East and West The 13th century world-system
Before the Mongols' rise, the Old World system consisted of isolated imperial systems. The new Mongol empire amalgamated the once isolated civilizations into a new continental system, and re-established the Silk Road as a dominant method of transportation. The unification of Eurasia under the Mongols greatly diminished the amount of competing tribute gatherers throughout the trade network and assured greater safety and security in travel. During the Pax Mongolica, European merchants like Marco Polo made their way from Europe to China on the well-maintained and well-traveled roads that linked Anatolia to China.
On the Silk Road traveled caravans with Chinese silk; pepper, ginger, cinnamon, and nutmeg came to the West from the Spice Islands via the transcontinental trade routes. Eastern diets were introduced to Europeans as well. Indian muslins, cottons, pearls, and precious stones were sold in Europe, as well as weapons, carpets, and leather goods from Iran. Gunpowder was also introduced to Europe from China. In the opposite direction, Europeans sent silver, fine cloth, horses, linen, and other goods to the near and far East. Increasing trade and commerce meant that the respective nations and societies increased their exposure to new goods and markets, thus increasing the GDP of each nation or society that was involved in the trade system. Sociologist Janet Abu-Lughod has noted that many of the cities participating in the 13th century world trade system grew rapidly in size.
Along with land trade routes, a Maritime Silk Road contributed to the flow of goods and establishment of a Pax Mongolica. This Maritime Silk Road started with short coastal routes in Southern China. As technology and navigation progressed these routes developed into a high-seas route into the Indian Ocean. Eventually these routes further developed encompassing the Arabian Sea, Persian Gulf, Red Sea, and the sea off East Africa.
Along with tangible goods, people, techniques, information, and ideas moved lucidly across the Eurasian landmass for the first time. For example, John of Montecorvino, archbishop of Peking founded Roman Catholic missions in India and China and also translated the New Testament into the Mongolian language. Long-distance trade brought new methods of doing business from the far East to Europe; bills of exchange, deposit banking, and insurance were introduced to Europe during the Pax Mongolica. Bills of exchange made it significantly easier to travel long distances because a traveler would not be burdened by the weight of metal coins.
Islamic methods of mathematics, astronomy, and science made their way to Africa, East Asia and Europe during the Pax Mongolica. Methods of paper-making and printing made their way from China to Europe. During the Pax Mongolica rudimentary banking systems were established, and money changing and credit extension were common, resulting in large amount of merchant wealth.
 Mongol administrationThe Mongol military was composed of cavalrymen who were able to cover large distances quickly
Mongolia's central geographical position on the Asian continent was an important reason why it was able to play such a large role in the trade system. The Mongol army was easily able to assert strong rule throughout most of the empire. The military ensured that supply lines and trade routes flowed smoothly; permanent garrisons were established along trade routes to protect the travelers on these routes. Complex local systems of taxation and extortion that were prevalent before Mongol rule were abolished to ensure the smooth flow of merchants and trade through the empire. A system of weights-and-measures was also standardized. To make the voyage on the trade routes less harrowing, the Mongols went as far as to plant trees along the roads to shade the merchants and travelers in the summer months; stone pillars were used to mark the roads where trees could not grow.