The Black Death caused a massive population decline contributed to the decline of the Mongol Empire. In the mid-14th century, the Black Death, a highly contagious and deadly disease, spread throughout Eurasia, severely affecting the populations of the Mongol Empire and causing a massive population decline. The population decline impacted the Empire's ability to collect taxes, recruit soldiers, and maintain control over the conquered areas, weakening the Empire and contributing to its decline. Although other factors such as excessive expansion, overworking of the land, and internal strife also played a role in the decline of the Mongol Empire.