Drogön Chögyal Phagpa
Zhogön Qögyä Pagba, Zhogoin Qoigyai Phagspa or Drogön Chögyal Phagpa (Tibetan: འགྲོ་མགོན་ཆོས་རྒྱལ་འཕགས་པ་, Wylie: 'Gro mgon Chos rgyal 'Phags pa; also written Dongon Choegyal Phakpa, Dromtön Chögyal Pagpa, etc.), born Lochö Gyäcän or Lochoi Gyaicain (1235–1280), was the fifth leader of the Sakya school of Tibetan Buddhism. He became the first vice-king of Tibet and played an important political role. He was also the guru and spiritual advisor to Kublai Khan, ruler of the Mongol Empire and the Yuan Dynasty.
Choegyal Phagpa Rinpoche (1235-1280): Nephew of Sakya Pandita and the fifth of the five patriarchs of the Sakya tradition. He became the spiritual mentor of the Kubilai Khan who established the Sakyas as the rulers of Tibet. Transformed Dzongsar Gonpa into a Sakya institution in 1275 when he returned from China.
[[Image:Sakya Pandita.jpg|thumb|left|Sakya Pandita)] In 1244, Sakya Pandita left for Prince Godan's royal camp with two of his young nephews, the ten year-old Phagpa and six year-old Chhana, who later published a collection of Sakya Pandita's writings. On the way, they stopped in Lhasa, where Phagpa took the vows of a young Buddhist monk at the Jokhang monastery in front of the statue of the Jowo offered by the Princess Wencheng, the Chinese wife of Songsten Gampo. Sakya Pandita preached sermons along his way and arrived at Prince Godan's camp in 1247 in Lanzhou in the current province of Gansu, where the Mongol troops were exterminating Chinese by throwing them in a river. Sakya Pandita, horrified, gave religious instructions, and in particular that killing a sentient being is one of the worst acts according to Buddha Dharma. He gave religious instruction to the prince and greatly impressed the court with his personality and powerful teachings. He is also said to have cured Prince Godan of a serious illness and, with the help of his nephew, Phagpa, he adapted the Uighur script so that the Buddhist Scriptures could be translated into Mongolian. In return, was given "temporal authority over the 13 myriarchies Trikor Chuksum of Central Tibet."
After the death of Sakya Pandita, Phagpa remained at the camp of Prince Godan and learned Mongolian language. Five years later Kublai Khan asked Godan to give him Chögyal Phagpa, who was then 23, and converted him to Buddhism. Shortly after, Kublai Khan in a succession fight, took over his brother, Möngke, and became the khan, the ruler of the Mongols and even later on became Emperor of China. Kublai Khan in turn appointed Chögyal Phagpa as his Imperial Preceptor in 1260 the year when he was proclaimed emperor of Mongolia. 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 priest-patron relationship. With the support of Kublai Khan, Chögyal Phagpa established himself and his sect as the preeminent political power in Tibet.
Kublai Khan commissioned Chögyal Phagpa to design a new writing system to unify the writing of his multilingual Yuan Dynasty. Chögyal Phagpa in turn modified the traditional Tibetan script and gave birth to a new set of characters called 'Phags-pa script which was completed in 1268. Kublai Khan decided to use the 'Phags-pa script as the official writing system of the empire, including when he became Emperor of China in 1271, instead of the Chinese ideogrammes and the Uyghur script. 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 Dynasty in 1368. The script was, though never widely, used for about a century and is thought to have influenced the development of modern Korean script.
Thus began a strong alliance and the capital of Sakya, gDan-sa, became the capital of Tibet. This lasted until about the middle of the 14th century. During the reign of the 14th Sakya Trizin, Sonam Gylatsen, the Central Tibetan province of U was taken by the Myriarch, marking the "beginning of the end of the period of Sakya power in Central Tibet."