Last Sung emperor defeated.

   Kublai, being a greedy ruler, wanted even more land. So, he went after the last Sung emperor.This would be the hardest defeat for the Mongols. The only way they had to get to places they wanted to defeat was by horse back. But, that posed a problem in this situation. Due to the fact that they would have to crossYangtze River and their horses couldn't cross it and it couldn't be done on foot. Eventually, they built ships and recruited Chinese sailors. From 1268-1273, they led a siege to the crossroads at Hsiang-yang. Then, they imported Muslim engineers to build catapults and mangonels. They used these to hurl huge boulders at the enemy. This was a big advantage that couldn't be dodged or stopped by the enemy. In 1276, they occupied the Sung capital of Lin-an.Then, the final battle happened at sea in 1279 where they defeated the last sung emperor where they were drowned.

"Kublai Khan — History.com Articles, Video, Pictures and Facts." History.com — History Made Every Day — American & World History. N.p., n.d. Web. 7 Dec. 2012. <http://www.history.com/topics/kublai-khan>.