system of the empire, including when he became Emperor of China in 1271, instead of Chinese characters or the Old Uyghur alphabet formerly used for Mongolian. However, he encountered major resistances and difficulties when trying to promote this script and never achieved his original goal. As a result, only a small amount of texts were written in this script, and the majority (including most official documents) were still written in Chinese ideograms or the Uyghur alphabet. The script fell into disuse after the collapse of the Yuan in 1368. The script was used for about a century and is thought to have influenced the development of Hangul. Phagpa's diaries for 1271 mention a foreign friend of Kublai Khan, who was quite possibly one of the elder Polos or even Marco Polo, although, unfortunately, no name is given. Creation of the Sakya-Yuan administrative system The Sakya-Mongol alliance was strong, and the seat () of the Sakya became the capital of Tibet. According to later historiography, Kublai Khan (who founded of the Yuan dynasty in 1271) granted the three cholka or regions of Tibet (Ü-Tsang, Amdo and Kham) to Phagpa as a reward for the initiation in the Buddhist faith. The donation would have taken place in 1253. However, this tradition has been qualified by recent research. As mentioned above, Kublai's brother and predecessor Möngke Khan divided Central Tibet into appanages obedient under various Mongol princes in 1251. In the next year he issued a decree saying that the main Buddhist precepts to be followed in Tibet were to be those of Sakya. In about 1260 the appanage system was withdrawn, and Phagpa, receiving the title State Preceptor (Guoshi), was acknowledged as the supreme head of the Buddhist clergy. In 1264, Kublai Khan established the Bureau of Buddhist and Tibetan Affairs. At about the same time, Phagpa was sent from the court to Tibet in order to persuade the local leaders to accept the imposition of Mongol administration. It was his first visit to his homeland since childhood. Phagpa received the new title of Imperial Preceptor (Dishi) in 1270, partly as a reward for his invention of the Phagpa script. As such, he was expected to stay close to the emperor and had a paramount influence over the Bureau of Buddhist and Tibetan Affairs. His decrees carried the weight of the imperial court which gave him a strong authority over Tibetan affairs.