Kublai Khan the role of Emperor of China. By 1279, the Mongol conquest of the Song dynasty was completed and Kublai became the first non-Han emperor to conquer all of China. The imperial portrait of Kublai was part of an album of the portraits of Yuan emperors and empresses, now in the collection of the National Palace Museum in Taipei. White, the color of the royal costume of Kublai, was the imperial color of the Yuan Dynasty. Kublai Khan was the fourth son of Tolui, and his second son with Sorghaghtani Beki. As his grandfather Genghis Khan advised, Sorghaghtani chose a Buddhist
Society of the Mongol Empire when the Song dynasty started replacing their copper coinage with paper currency. When the Mongols invaded Song China they started issuing their own Mongolian bills in 1227. This first attempt by the Mongols did not last long because the notes issued expired after several years and were inconsistent throughout the parts of the Mongol Empire that issued them. In 1260, Kublai Khan created the Yuan Mongol's first unified paper currency with notes that did not have any expiration date. To validate the currency, it was made fully exchangeable to silver and gold and was accepted as tax payments. Currency distribution