Final answer:
The Yuan Dynasty was undermined by lavish military spending, unchecked inflation, mismanagement in the face of natural disasters, and political instability following Kublai Khan's death, culminating in its replacement by the Ming Dynasty.
Step-by-step explanation:
The policies that undermined Yuan authority included lavish military expenditures, inflation, and the failure to effectively respond to natural disasters and famines. Yuan rulers, especially after Kublai Khan, depleted the treasury with unsuccessful military campaigns such as the invasions of Vietnam, Japan, and Java.
These ventures were costly and drained resources needed elsewhere. Inflation exacerbated the problem, leading to increased taxation and economic hardship for the peasant class. Furthermore, natural disasters like droughts and floods, followed by famines, weakened the population and increased discontent. Additionally, the Yuan dynasty's failure to effectively address banditry and maintain control over the army contributed to the diminishing law and order, further destabilizing their rule.
The political instability following Kublai Khan's death also played a significant role in undermining Yuan authority. A succession crisis with seven emperors in just twenty-six years led to a lack of strong, consistent leadership.
This period of chaos, coupled with the government's mismanagement of resources and natural calamities, created an environment ripe for rebellion. Eventually, widespread revolts and the impact of the bubonic plague were the final blows to the weakening Yuan dynasty, leading to its collapse and the rise of the Ming dynasty.