Chaigneau was one of the most respected advisors to Emperor Gia Long. He spent more than 30 years in  Cochinchina  and became the first French  Consul  to this  kingdom  in 1821. [28] In 1821, the  Lịch Triều Hiến Chương Loại Chí  published by Phan Huy Chú, a historian, an encyclopaedist, and