The most important publication of the Historiographical Institute is the still-to-be-completed, 343+ volume "Dai-Nihon shiryō". It consists of primary source material from the 887 to 1867, and is organized chronologically by major historical events. Institute members have been working on the "Dai-Nihon shiryō" ever since the foundation of the Shiryō hensan-jo in 1869; many of the Institute's publications (listed in the link above) are simply companions to the "Dai-Nihon shiryō" such as the "Shiryō sōran", which is a chronological list of historical events that are used to categorize material in the "Dai-Nihon shiryō". When completed, it will be the most comprehensive collection of Japanese historical materials ever. This collection primarily consists of primary sources, but also includes secondary sources, interpretative essays, and even fictional accounts when no other sources can be found. The variety of source materials in this work includes formal histories, government documents, letters, journals, biographies, temple records, and family archives.