The 'Phags-pa script, (Mongolian: дөрвөлжин үсэг «Square script») was an alphabet designed by the Tibetan monk and vice-king Drogön Chögyal Phagpa for the Mongol Yuan emperor Kublai Khan as a unified script for the literary languages of the Yuan. Widespread use was limited to about a hundred years during the Yuan Dynasty, and it fell out of use with the advent of the Ming dynasty. The documentation of its use provides clues about the changes in the varieties of  Chinese 4E00–9FFF , the  Tibetic 0F00–0FFF languages, Mongolian and other neighboring languages during the Yuan era.