Mr. Green, Mr. Green, but horses don't have feet. They have hooves. I hate you, me from the past. Also, no interrupting the Thought Bubble. After uniting the Mongols, Genghis Khan went on to conquer a lot of territory. By the time he died in his sleep in 1227, his empire stretched from the Mongol homeland in Mongolia all the way to the Caspian Sea. Thanks, Thought Bubble.