remaining Ming Chinese in Vietnam. The return of the Ming Chinese to China was commanded by the Ming and not Le Loi. The Trai made up the supporters of Le Loi in his campaign. He lived among the Trai at the border regions as their leader and seized the Ming-ruled lowland Kinh areas after originally forming his base in the southern highland regions. The southern dwelling Trai and Red River dwelling Vietnamese were in effect locked in a "civil war" during the anti-Ming rebellion by Le Loi. The leader Lưu Bác Công (Liu Bogong) in 1437 commanded a Dai Viet military squad made out of ethnic Chinese since even after the independence of Dai Viet, Chinese remained behind. Vietnam received Chinese defectors from Yunnan in the 1400s. The Vietnamese Ruler Le Thanh Tong cracked down on foreign contacts and enforced an isolationist policy. A large amount of trade between Guangzhou and Vietnam happened during this time. Early accounts recorded that the Vietnamese captured Chinese whose ships had blown off course and detained them. Young Chinese men were selected by the Vietnamese for castration to become eunuch slaves to the Vietnamese. It has been speculated by modern historians that Chinese who were captured and castrated by the Vietnamese were involved in regular trade between China and Vietnam instead of being blown off course, and that they were punished after a Vietnamese crackdown on trade with foreign countries. A 1499 entry in the Ming Shilu recorded that thirteen Chinese men from Wenchang including a young man named Wu Rui were captured by the Vietnamese after their ship was blown off course while traveling from Hainan to Guangdong's Qin subprefecture (Qinzhou), after which they ended up near the coast of Vietnam, in the 1460s, during the Chenghua Emperor's rule (1464–1487). Twelve of them were enslaved to work as agricultural laborers, while the youngest Chinese man, Wu Rui (吳瑞) was selected by the Vietnamese court for castration since he was the only young man in among the thirteen and he became a eunuch at the Vietnamese imperial palace in Thang Long for nearly one fourth of a century. After years of serving the Vietnamese as a eunuch slave in the palace, he was promoted to a position with real power after the death of the Vietnamese ruler in 1497 to a military position in Northern Vietnam as military superintendent since his service in the