Imperial Preceptor in the context of "Sakya (Tibetan Buddhist school)"

The Era of Fragmentation (Tibetan: སིལ་ཆད་དུ་འཆད་པ) was an era of disunity in Tibetan history lasting from the death of the Tibetan Empire's last emperor, Langdarma, in 842 until Drogön Chögyal Phagpa became the Imperial Preceptor of the three regions of Tibet in 1253, following the Mongol conquest in the 1240s. During this period, the political unity of the Tibetan Empire collapsed following the Battle of U-Yor [zh] between Yumtän (Yum brtan) and Ösung (’Od-srung), after which followed numerous rebellions against the remnants of imperial Tibet and the rise of regional warlords.

Drogön Chogyal Phagpa (Tibetan: འགྲོ་མགོན་ཆོས་རྒྱལ་འཕགས་པ།, Wylie: ʼgro mgon chos rgyal ʼphags pa), who lived from (26 March 1235 – 15 December 1280), was the fifth leader of the Sakya school of Tibetan Buddhism. He was also the first Imperial Preceptor of the Yuan dynasty and was concurrently named the director of the Bureau of Buddhist and Tibetan Affairs, serving during the reign of Kublai Khan.

Historical tradition remembers him as the first vice-ruler of Tibet under the Yuan emperor as well as one of the Five Sakya patriarchs (Tibetan: ས་སྐྱ་གོང་མ་རྣམ་ལྔ་, Wylie: sa skya gong ma rnam lnga). Although this is historically disputed, he played a very important political role.

The priest and patron relationship, also written as priest–patron or cho-yon (Tibetan: མཆོད་ཡོན་, Wylie: mchod yon; Chinese: 檀越關係; pinyin: Tányuè Guānxì), is the Tibetan political theory that the relationship between Tibet and China referred to a symbiotic link between a spiritual leader and a lay patron, such as the historic relationship between the Dalai Lama and the Qing emperor. They were respectively spiritual teacher and lay patron rather than subject and lord. Chöyön is an abbreviation of two Tibetan words: chöney, "that which is worthy of being given gifts and alms" (for example, a lama or a deity), and yöndag, "he who gives gifts to that which is worthy" (a patron).

During the 1913 Simla Conference, the 13th Dalai Lama's negotiators cited the priest and patron relationship to explain the lack of any clearly demarcated boundary between Tibet and the rest of China (ie. as a religious benefactor, the Qing did not need to be hedged against). According to this concept, in the case of Yuan rule of Tibet in the 13th and 14th centuries, Tibetan Lamas provided religious instruction; performed rites, divination and astrology, and offered the khan religious titles like "protector of religion" or "religious king"; the khan (Kublai and his successors), in turn, protected and advanced the interests of the "priest" ("lama"). The lamas also made effective regents through whom the Mongols ruled Tibet. According to Sam van Schaik, the Mongols ruled Tibet not as an administrative province of the Yuan dynasty but as a Mongol colony. The Bureau of Buddhist and Tibetan Affairs and Imperial Preceptor in Khanbaliq were at the top of the Tibetan administration, but due to the great distance from Tibet, they had little direct influence on daily governance. Hence, the highest authority in Tibet was the administrator of the Sakya who deferred to the abbot in religious matters.

Qingliang Chengguan (Chinese: 澄觀; pinyin: Chéngguān; Korean: Jinggwan; Japanese: Chōgan, 738–839 or 737-838 CE), was an important scholar-monk and patriarch of the Huayan school of Chinese Buddhism also known as Huayan pusa (bodhisattva Avatamsaka) and Qingliang Guoshi (Imperial Preceptor "Clear and Cool", Clear and Cool is a name for Mount Wutai).

Chengguan is most widely known for his extensive commentaries and sub-commentaries to the Avataṃsaka Sūtra (Huayan jing), as well as for his translation of a new Gandhavyuha sutra version, together with the Indian monk Prajña. Chengguan's commentaries on the Avataṃsaka quickly became one of the authoritative sources for Huayan doctrine. Chengguan lived through the reigns of nine emperors and was an honored teacher to seven emperors starting with Xuanzong (玄宗) until Wenzong (文宗). Chengguan was also the teacher of the influential Huayan patriarch Zongmi.

The Phagspa (/ˈpɑːɡzˌpɑː/ PAHGZ-PAH), ʼPhags-pa or ḥPʻags-pa script is an alphabet designed by the Tibetan monk and State Preceptor (later Imperial Preceptor) Drogön Chögyal Phagpa (1235–1280) for Kublai Khan (r. 1264–1294), the founder of the Yuan dynasty (1271–1368) in China, as a unified script for the written languages within the Yuan. The actual use of this script was limited to about a hundred years during the Mongol-led Yuan dynasty, and it fell out of use with the advent of the Ming dynasty.

The script was used to write and transcribe varieties of Chinese, the Tibetic languages, Mongolian, the Uyghur language, Sanskrit, probably Persian, and other neighboring languages during the Yuan era. For historical linguists, its use provides clues about changes in these languages.