Buyantu Khan (Mongolian: Буянт хаан; Mongolian script: ; ), born Ayurbarwada (Mongolian: Аюурбарбад ; ), also known by the temple name Renzong (Emperor Renzong of Yuan (Chinese: 元仁宗, April 9, 1285 – March 1, 1320), was the fourth emperor of the Yuan dynasty of China. Apart from Emperor of China, he is regarded as the eighth Great Khan of the Mongol Empire, although it was only nominal due to the division of the empire. His name means "blessed/good Khan" in the Mongolian language. His name "Ayurbarwada" was from a Sanskrit compound "Āyur-parvata" (), which means "the mountain of longevity", in contrast with Emperor Wuzong's name Qaišan (海山, "mountains and seas" in Chinese). Ayurbarwada was the first Yuan emperor who actively supported the adoption of Confucian principles into the administration system. The emperor, who was mentored by the Confucian academic Li Meng, succeeded peacefully to the throne and reversed his older brother Khayisan's policies. More importantly, Ayurbarwada reinstituted the civil service examination system for the Yuan dynasty. Struggle for succession Ayurbarwada was the second son of Darmabala and Dagi (Targi) of the Khunggirat, and a great-grandson of Kublai Khan (r. 1260–1294). He had been tutored by the Confucian scholar Li Meng, who strongly affected his future political attitudes since his early teens. In 1305 Bulugan Khatun removed Ayurbarwada from the court and sent him to Honan as the prince of Huai-ning. However, his uncle Temür Khan died without an heir on February 2, 1307, because his son Tachu had died a year earlier before him. Temür's widow Bulugan of the Bayaud tribe had kept away the Khunggirad-mothered brothers of Khayishan and Ayurbarwada and attempted to set up her favorite, the Muslim Ananda, their uncle and the governor of Ningxia. The Darkhan Harghasun, the right chancellor () of the government who became aware of Bulugan's plan, recalled Ayurbarwada and Li Meng from Huaizhou () to the capital Dadu. They successfully developed a strategy to imprison both Ananda and Bulugan. Afterwards, Ayurbarwada welcomed his older brother Khayishan, who was still far away from Dadu, to succeed to the throne. After the latter's coronation, Ayurbarwada was appointed the Crown Prince in June 1307. The brothers promised each other that their descendants would rule in succession. Early career under Külüg Khan and enthronement Ayurbarwada was made head of the top central administrative organs known as the Zhongshu Sheng under his brother and predecessor Khayishan Külüg