The Collection of the Essentials of the Nguyen Dynasty under the Dong Khanh Reign and Khai Dinh Reign was edited from October 1922 to June 1923. It composed of two parts: Part One - Dong Khanh Essentials that wrote up all main events & happenings that took place in 3 years ( from August 1885 to December 1888 ). Part Two: Khai Dinh Essentials that wrote up all main events & happenings that took place from April 1916 to December 1923. An advantage of the Collection is that all main events & happenings were selected carefully, based on official written deeds / materials and arranged by topics ( such as: The ceremonies of throne's coming. Respecting & thank-giving to the Sky & Forefathers. Family history & teachings for the descendants. Striving for self-improvement. Pro-people policy. The Courts staff & cadre policy. Law-making activity. Reward & punishment. Cultural, military & political policies, matters & events. Mandarinate organization. Diplomacy....And many others. ). The Collection is a kind of official records of the Royal Courts that reflected a special historic period of the Nation.