Chu Van An was born in 1292 in Van Thon village, Quang Liet commune, present day ThanhTri district, Hanoi. In the early life, he was famous as a straightforward man who passed the doctoral examination but refused to become a mandarin. Instead, he opened a school and began his career as a Confucian teacher in Huynh Cung village in Thanh Tri. Under the reign of Tran Minh Tong, Chu Van An became a teacher at the Imperial Academy where he was responsible for teaching the crown prince Vuong, the future emperor Tran Hien Tong. Later, he resigned and returned to his home-village because Tran Du Tong refused his request of beheading eight corrupted mandarins. For the rest of his life, Chu Van An continued his teaching career and wrote books. He died of illness in 1370.    1.   When was Chu Van An born?