 After Genghis Khan 's death in 1227 , his empire was divided by his descendants into four sections or Khanates , which degenerated into civil war . The northwestern Kipchak Khanate , known as the Golden Horde , expanded towards Europe , primarily via Hungary and Poland , while its leaders simultaneously opposed the rule of their cousins back at the Mongol capital . The southwestern section , known as the Ilkhanate , was under the leadership of Genghis Khan 's grandson Hulagu . He continued to support his brother , the Great Khan , and was therefore at war with the Golden Horde , while at the same time continuing an advance towards Persia and the Holy Land . 
