 Complete the following phrase:  The Yuan dynasty was formally proclaimed in 1271, when the Great Khan of Mongol, Kublai Khan, one of the grandsons of Genghis Khan, assumed the additional title of Emperor of China, and considered his inherited part of the Mongol Empire as a Chinese dynasty. In the preceding decades, the Mongols had conquered the Jin dynasty in Northern China, and the Southern Song dynasty fell in 1279 after a 