Nguyen Duc Xuyen (1759-1824) is the 15th descendant of the Nguyen family. He was a high-ranking mandarin under Emperor Le Trung Hung. In 1822, Emperor Minh Mang ordered the officials who held important positions in the court to write the record of events and incidents, and gather them to make historical documents. Nguyen Duc Xuyen wrote this document in his chronological style. The content includes everything related to Nguyen Duc Xuyen's official duties during 43 years. The majority of this document describes the fighting process of the Nguyen army, from 1780 until capturing Thang Long, with specific battles in the areas of Southern, Phu Yen, Dien Khanh, Quy Nhon, Nam Ngai ... This document is valuable in terms of literature, geography, especially early modern history, in the fields of military, internal affairs, diplomacy and foreign trade of the early Nguyen Dynasty.