Drogön Chögyal Phagpa
The traditional Mongolian alphabet is not a perfect fit for the Mongolian language, and it would be impractical to extend it to a language with a very different phonology like Chinese. Therefore, during the Yuan Dynasty (ca. 1269), Kublai Khan asked a Tibetan monk, Drogön Chögyal Phagpa, to design a new script for use by the whole empire. Phagpa extended his native Tibetan script to encompass Mongolian and Chinese; the result was known by several descriptive names, such as the "Mongolian new script", but today is known as the 'Phags-pa script. The script did not receive wide acceptance and fell into disuse with the collapse of the Yuan dynasty in 1368. After this it was mainly used as a phonetic gloss for Mongols learning Chinese characters. However, scholars such as Gari Ledyard believe that in the meantime it was the source of some of the basic letters of the Korean hangul alphabet.