Europeans viewed the spread of Islam as a threat and actively worked to stop it.
Mongol<span> expansion into Central Asia began in 1209, as the </span>Mongols<span> pursued tribal leaders who opposed Chinggis Khan's </span>rise to power<span> in Mongolia and thus constituted a threat to his authority there. With their victories, the </span>Mongols gained<span>new territory. ... Indeed, the </span>Mongols<span> cultivated this idea.
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I'm not sure if this is the answer, but they were backed by China