On this day, 835 years ago, July 24, 1190 (June 20, the 1190 lunar calendar), Yelu Chucai, the "master of the world", was born. On July 24, 1190, Yelu Chucai, known as the "master of governing the world", was born. Yelu Chucai was a Khitan who was proficient in Han culture. He was the ninth grandson of Yelu ABaoji, the founding emperor of the Liao Dynasty. He had read extensively since childhood and was proficient in astronomy, geography, calendar, mathematics, and medicine. He also served as a minor official in the Jin Dynasty. In 1215 AD, Genghis Khan captured Zhongdu (now Beijing City). When he heard that Yelü Chucai was very talented, he ordered him to be summoned and asked him to do things beside him, calling him "Wotusahali." "Wutusahali" means Mongolian long beard. Later, Yelu Chucai followed Genghis Khan on his westward expedition. Because he could divination and his predictions often came true, Genghis Khan valued him more. After the death of Genghis Khan, Ogetai ascended the throne and became a Khan. He reused Yelü Chucai, which enabled Yelü Chucai to play a greater role in changing the governance and exploitation methods of Mongolia. Although Mongolia is divided into noble and humble, it has never had a strict distinction between monarch and minister like the feudal dynasties in the Central Plains. After Wogotai was elected as the Great Khan, Yelu Chucai said to Chagatai,"Although you are the brother of the Great Khan, in terms of status, you are a courtier and should kneel down to the Great Khan." If you take the lead in kneeling down, no one will dare not to bow down." Therefore, Chagtai led the gold family and officials at all levels to bow to Khan Wogotai. From then on, Mongolia had the courtesy of honoring Khan. At the beginning of the founding of the People's Republic of China, Mongolia implemented a system of integrating military and political affairs. There were only ten thousand households, thousands of households, and hundreds of households who commanded the army, and no officials who governed political affairs. In order to change this situation, Yelu Chucai made suggestions: "Local officials should be set up to rule the people, and another ten thousand households should be set up to manage the army, so that the military and government can contain each other and prevent arbitrary decisions." Woguitai adopted it. Based on his suggestion, Wogetai established the highest administrative agency in the central government, the Ministry of Central Affairs, and appointed Yelu Chucai as the Ministry of Central Affairs (prime minister). When the Mongolian army invaded Asian and European countries and conquered various ethnic groups in the country, there was such a rule: whenever the enemy's towns were attacked, as long as the other party resisted, once conquered, no matter how old or young, rich or poor, or obedient, except for craftsmen, most of them were killed, and a few women and children became slaves. Yelu Chucai suggested that all skilled craftsmen and large households with wealth should be concentrated in Bianjing City, and these people should not be killed. Wogei felt that it made sense and adopted Yelu Chucai's suggestion. From then on, the number of Mongolian troops slaughtering cities gradually decreased. Mongolia did not originally formulate complete laws. Yelu Chucai proposed the "Eighteen Cheap Things" as a temporary law, strictly prohibiting local officials from killing ordinary people without authorization, prohibiting businessmen and rich people from embezzling public property, cracking down on local ruffians and hooligans, and prohibiting landlords and rich people from seizing farmers 'lands. In this way, social order gradually settled down. In addition, Yelu Chucai also advocated using the teachings of Confucius and Mencius as the criterion for governing the country and the people, and selected Confucian scholars to serve as officials at all levels. Yelu Chucai is worthy of being a "master of the world" and has made important contributions to the development of Mongolia. However, after the death of Ogetai, Yelu Chucai was no longer important. Yelu Chucai assisted Genghis Khan and Ogetai in governing the country for nearly 30 years and died in 1244 AD. In order to commemorate Yelu Chucai's achievements, people built a special memorial temple for him, which is still preserved in the Summer Palace in Beijing.