I believe that the Mongols were unhappy with Kublai Khan's rule because Kublai Khan's Chinese governance, centralized control, and high taxation policies, which the Mongols felt violated their identity and placed an enormous burden on them.

One reason that I know they were unhappy with his leadership is________________________________________________________________.

because historical records show that many Mongol nobles and warrior clans resisted Kublai Khan's attempts to assert his authority over them, leading to several rebellions and armed conflicts throughout his reign. Additionally, the imposition of Chinese bureaucratic systems and cultural assimilation policies alienated many Mongols who saw themselves as distinct from the Chinese people. This eventually led to a decline in the loyalty and support of the Mongol population towards Kublai Khan and his rule.