of their fiefs in consultation with the Sakya envoys and in accordance with Mongol law. Entering the service of Kublai Khan After the death of Sakya Pandita, the Mongol ruler Möngke Khan dispatched new military campaigns against parts of Tibet in 1252–53. He furthermore shared up the main Tibetan sects among the ruling clan. While he patronized the Drikung Kagyu, Godan protected Sakya and there were at least nine further appanages. Phagpa and his brother remained at the camp of Godan, learned the Mongolian language and took up Mongol dress. Möngke's brother Kublai, after a brief flirtation with Chan Buddhism, found Tibetan Buddhism more to his liking. In 1253 he asked Godan to give him Chögyal Phagpa, who was then 18. Kublai was subsequently converted to Buddhism by his efforts and Phagpa became his tantric guru in 1258. Under the influence of Kublai's wife Chabi, their mutual relation was defined so that Phagpa had a precedence in religious matters and Kublai in temporal affairs. When the prince received religious instruction from his lama, the latter sat on a higher seat, while Kublai sat higher than Phagpa when he conducted court business. Phagpa further strengthened his case by defeating his Daoist opponents in a great debate in Kublai's newly built city Kaiping in 1258. Shortly after, Kublai Khan took power in a succession struggle after the death of his brother Möngke in 1259. He thereby became the Khagan, the ruler of the Mongols; later on, he became the Emperor of China. Phagpa supported the new lord by presenting him as a chakravartin or universal ruler. Kublai Khan in turn appointed Chögyal Phagpa as his National Preceptor (Guoshi) in 1260, the year when he was proclaimed Khagan. According to Mongol sources, Phagpa was the first one "to initiate the political theology politics of the relationship between state and religion in the Tibeto-Mongolian Buddhist world" - that is to say, he developed the concept of the patron and priest relationship. With the support of Kublai Khan, Chögyal Phagpa established himself and the Sakya as the preeminent political power in Tibet. Development of the Phagpa script Kublai Khan commissioned Chögyal Phagpa to design a new writing system to unify the writing of the multilingual Yuan China. Phagpa modified the Tibetan alphabet to create his ʼPhags pa script, which was completed in 1269. Kublai Khan decided to use the ʼPhags-pa script as the official writing