From Google stream Kublai

In 1259, the great Mongol Empire — which stretched from parts of China west to Russia — was shaken for the second time by the death of its leader, or khan, when Möngke, a grandson of the founder Genghis Khan, died. One of his brothers, Kublai, left his army in China, came back to Mongolia, and had himself declared the Great Khan.

When he took the throne, Kublai was in his forties. He was the fourth son of the fourth son of Genghis and had only about a decade’s experience in military and political leadership. But he proved his worth and justified the name given him by Mongols, Setsen Khan, or “the Wise Khan.”
Shortly after taking the throne, Kublai returned to his efforts to complete the Mongol conquest of China. The Mongols’ superb cavalry had easily overrun other lands across Central Asia, but that type of force was less effective in river-crossed and highly-urbanized China. Following the advice of Chinese advisors, Kublai built a fleet that navigated the rivers and made it possible to defeat the towns. By 1279, he was fully in control of China.
Ironically, Kublai’s focus on China cost him control of the larger empire. During the conquest of China, regional leaders in the western parts of the Mongol Empire broke away, creating rival states.
The Great Khan was probably quite content with China and Mongolia, however. In 1264, he moved his capital from Karakorum to Beijing, making it the capital of China for the first time. That capital was magnificent — as attested to by Venetian merchant Marco Polo, who reached it a few years later. Polo called the Khan’s palace “so vast, so rich, and so beautiful, that no man on earth could design anything superior to it.”
Kublai ruled until his death in 1294. While his rule was a time of prosperity for China, his Yuan dynasty he founded lasted less than a hundred years. http://blog.oup.com/2012/05/kublai-khan-becomes-mongol-emperor/