He sought to create a single alphabet that could be used to write all the languages of the world. He assigned this task to the Tibetan Buddhist lama Phagspa, who in 1269 presented the khan with a set of forty-one letters derived from the Tibetan alphabet.
(quoting Genghis Khan: And the making of the Modern World by Jack Weatherford)
Reminds me, it's time to pick up another copy of Calvino's Invisible Cities. You really ought to read that book.