When the fourth Mongol great khan, Möngke, died in 1259, his brother, Kublai, never doubted who was his rightful successor. While Möngke had been expanding Mongol rule into Syria in the far west, Kublai had proved to be a brilliant general, conquering a swath of what is now southwestern China as well as modern-day Vietnam. He had proved his mettle, but there were others who sought to rule.
News reached Kublai that another of his brothers, Arigböge, also wanted to proclaim himself emperor. Kublai, then age 45, hastily made his way to his residence at Shangdu (later immortalized as Xanadu in Samuel Taylor Coleridge’s famous poem “Kubla Khan”) to decide what to do next. (Out of Eden: National Geographic Explorer Paul Salopek reports from Xanadu.)
Kublai knew that whoever succeeded Möngke would need formidable diplomatic as well as military skills to hold together a colossal patchwork of lands that stretched from northern China through Persia to Russia. To face down the threat from Arigböge he chose an impressive ritual that would give him unshakable legitimacy. After consulting his advisers, Kublai decided to cement his claim by casting the I Ching, an ancient Chinese system of divination with links to both Confucianism and Taoism. The solemn rite revealed that Kublai would achieve sublime success if he persevered along the correct path.