is a historical text that categorizes and chronologizes the events listed in the Six National Histories

Rikkokushi

is a general term for Japan's six national histories chronicling the mythology and history of Japan from the earliest times to AD 887. The six histories were written at the imperial court during the eighth and ninth centuries, under order of the Emperors...

. It was compiled by Sugawara no Michizane

Sugawara no Michizane

, also known as Kan Shōjō , a grandson of Sugawara no Kiyotomo , was a scholar, poet, and politician of the Heian Period of Japan...

 and completed in 892. The text was commissioned by Emperor Uda

Emperor Uda

was the 59th emperor of Japan, according to the traditional order of succession.Uda's reign spanned the years from 887 through 897.-Name and legacy:Before his ascension to the Chrysanthemum Throne, his personal name was or Chōjiin-tei....

.

Contents

The text was originally 200 volumes in length with two indexes and three genealogical volumes. However, much of it was lost during the Ōnin War

Onin War

The ' was a civil war that lasted 10 years during the Muromachi period in Japan. A dispute between Hosokawa Katsumoto and Yamana Sōzen escalated into a nationwide war involving the Ashikaga shogunate and a number of daimyo in many regions of Japan....

 in the late 15th century. Only 62 volumes are currently extant: volumes 1-5, 8-11, 14-16, 19, 25, 28, 31-36, 40, 54, 61, 66, 71-75, 77-80, 83-84, 86-89, 99, 101, 107, 147, 159, 165, 170-171, 173, 177-180, 182, 185-187, 189-190, 193-194, 199.

The text categories and subcategories the historical accounts given in the Six National Histories, listing each of which in chronological order.. There are a total of eighteen categories, with another five lost in the missing volumes.

While the final national history, Nihon Sandai Jitsuroku

Nihon Sandai Jitsuroku

, abbreviated as Sandai Jitsuroku, is an officially commissioned Japanese history text. Completed in 901, it is the sixth and final text in the Six National Histories series. It covers the years 858-887.-Background:...

, was completed in 901, nine years later, Michizane was one of the contributing editors and was thus able to incorporate early content.

The editorial policy was to be true to the original sources without modifying or adding to the content. It is thus a valuable resource in reconstructing Nihon Kōki

Nihon Koki

is an officially commissioned Japanese history text. Completed in 840, it is the third volume in the Six National Histories. It covers the years 792-833.-Background:...

, Shoku Nihon Kōki

Shoku Nihon Koki

is an officially commissioned Japanese history text. Completed in 869, it is the fourth volume in the Six National Histories. It covers the years 833-850.-Background:...

, and Nihon Sandai Jitsuroku

Nihon Sandai Jitsuroku

, abbreviated as Sandai Jitsuroku, is an officially commissioned Japanese history text. Completed in 901, it is the sixth and final text in the Six National Histories series. It covers the years 858-887.-Background:...

, all of which were largely lost over time.