|Beginning of Mongol Collapse: Public Works Failures
Public-works projects that the Mongols initiated in China:
the building of the capital city in Daidu (Beijing) $$
the construction of a summer capital in Shangdu $$$$$
the building of roads and a network of postal stations $$$$$$$$
the extension of the Grand Canal $$$$$$$$$$$
All extraordinarily costly! $$$$$$$$$$
All these projects required vast investments of labor and money obtained through exceptionally high taxation upon the peasants and the merchants. Toward the end of Kublai Khan's reign, the Mongols resorted to a deliberate inflation of the currency to cover costs. These financial problems undermined the economy, and before long the Mongols could no longer maintain even the public-works projects traditionally supported by the native Chinese dynasties, such as the Grand Canal or the irrigation-control projects along the Yellow and Yangtze Rivers. The results were predictable.
In the 1340s terrible floods erupted, changing the course of the Yellow River and leaving a large group of people homeless and wandering around the countryside amid much confusion and destruction. Ultimately, some of these bands of unemployed and homeless peasants united into a rebel force, and in the 1350s began the process of ousting the Mongols from China. By the mid-1360s, many of the Mongols had already returned to Mongolia, and the Ming dynasty, a native Chinese dynasty, finally took back control of China in 1368.
Current day note: The rivers of China are still some of the most destructive in the world. Three Gorges Dam was completed in 2012 to control the flooding and is as powerful as 15 nuclear reactors! It is highly controversial since it caused ecological damage and displaced 1.3 million Chinese.
Beginning of Mongol Collapse: Military Successes and Failures
In the initial days of their rule in China, Kublai Khan and the Mongols had remarkable military successes, their greatest victory being the conquest of Southern Song China by 1279 C.E. This particular campaign, for which the Mongols had to organize a navy in order to cross the Yangtze River and move into southern China, entailed tremendous logistical efforts. Ultimately, though, the failure of their military campaigns in Japan became a key factor leading to the weakening and eventual demise of the Mongol empire in China.
Cog and Galley: Mongol Fleets in Southern China
Further Decline of Mongol Control
Expeditions such as the Japanese attacks were extremely costly and weighed heavily upon the Mongol rulers in China. In 1292 an expedition against Java, also a disaster, only served to further weaken the Mongols' resources and resolve. The Mongols actually managed to land in Java, but the heat, tropical environment, and parasitic and infectious diseases there led to Mongol withdrawal from Java within a year.
Similar problems afflicted the Mongols in all their attacks and invasions into mainland Southeast Asia — in Burma, Cambodia, and in particular, Vietnam. Though they initially succeeded in some of these campaigns, the Mongols were always forced to withdraw eventually because of adverse weather and diseases. It would seem that the Mongols simply were not proficient in naval warfare and did not have much luck in surviving infectious diseases in this part of the world. And with each failed campaign, vast sums were expended, and the empire was further weakened.