Shoku Nihongi (Chronicle of Japan Continued) (続日本紀)
Shoku Nihongi is a collection of history books which was compiled by Imperial command in the early Heian period. It is the second book of the Rikkokushi (the Six National Histories), and came out after "Nihon Shoki" (Chronicles of Japan). SUGANO no Mamichi and others completed the book in 797. It consists of 40 volumes in total and covers 95 years, ranging from 697, the first year of the Emperor Monmu's reign, to 791, the reign of Emperor Kanmu. It is the fundamental historical material to know the Nara period. It was arranged in chronological order and written in classical Chinese.
The first and second halves of the book were compiled for different reasons.
The first half of the book was originally planned to consist of 30 volumes in total and cover the years ranging from 697, the first year of the Emperor Monmu's reign, to 757, the reign of Empress Koken. Emperor Konin ordered ISHIKAWA no Natari, OMI no Mifune, and TAIMA no Nagatsugu to revise the work, but they lost A Record of the First Year of the Tenpyo Hoji Era and could not finish the revision (there is an opinion that due to the many political conflicts which occurred before and after the year 757, they could not reach an agreement about writing the history, so they pretended that it had been lost). Emperor Kanmu ordered SUGANO no Mamichi, AKISHINO no Yasuhito, and NAKASHINA no Kotsuo to complete the work, and thus the volumes totaled 20.
Emperor Kanmu gave an order to compile the latter half of the book that was supposed to deal with the history dating from 758 to perhaps 777 (the reigns of Emperor Junnin to Emperor Konin). The 20-volume work which had been compiled by ISHIKAWA no Natari and KAMITSUKENU no Okawa was reduced to 14 volumes by FUJIWARA no Tsugutada, SUGANO no Mamichi, and AKISHINO no Yasuhito, then it was completed in 794. SUGANO no Mamichi, AKISHINO no Yasuhito and NAKASHINA no Kotsuo added six more volumes to the work, which covered the incidents that had occurred before 791 in the reign of Emperor Kanmu, thus brought the total to 20 volumes.
It was in 797 that the work consisting of 40 volumes in total was completed.
There are differences in contents between the imperial collections of the history books "Nihon Shoki," which described the process of unifying the country of "Japan," and "Zoku Nihonshi," which dealt with the history of the country after its formation. Thanks to the Ritsuryo system (a system of centralized government based on the ritsuryo code), Naiki (Secretary of the Ministry of Central Affairs), Geki (Secretary of the Grand Council of State) and Zushoryo (the Bureau of Drawings and Books) developed a method of collecting records and official documents, although it was not yet perfect; this development led to the collection of records rich in content.
As a whole, it was written concisely, and only the gist of the incidents was described, so it does not contain the details. It was sometimes written so briefly that important things such as the Yoro ritsuryo code (code promulgated in the Yoro period) were omitted. The brief biographies were added to some of the obituaries, and this style was followed by the succeeding history books. Such biographies were called Koden.
The articles concerning the reign of Emperor Kanmu were written with extra political consideration. The article on the disinherited Imperial Prince Sawara, by which the Emperor was distressed, was once included in the book, however it was deleted along with the article on the assassination of FUJIWARA no Tanetsugu; both articles triggered the incident. The deleted articles were re-entered during the reign of Emperor Heijo, but Emperor Saga deleted them again. Those articles were recorded in "Nihongi Ryaku" (Summary of Japanese Chronologies). This seems to have had something to do with the legend that Imperial Prince Sawara had become a vengeful ghost.
Some people say that an article about FUJIWARA no Hirotsugu, a rebel in the Fujiwara no Hirotsugu War, was presented in a good light. Moreover, there is a view that articles about both a plot by the oracle of Usa Hachiman-gu Shrine and Dokyo, a Buddhist priest, contained political intent. Compared with "Nihon Shoki," however, Shoku Nihongi is considered much more reliable. It is the first history book which was organized as a set of accurate, full-scale records, elucidating various aspects of the "Tenpyo culture."
"Shoku Nihongi" was followed by the records of "Kanso Jirui" (Classified Materials as an Aid to Officials) and "Gekan Jirui (Classified Guide for Provincial Officials"). The former consisted of the categorized original documents that had been omitted from the book. The contents of the latter records are unknown, but it seems to have been similar to the former. Both records were lost.