Heihan ki (兵範記)

Heihan ki (or Hyohan ki) is a diary written by TAIRA no Nobunori who was a court noble in the Heian period. The title of the book came from both Nobunori's name and a position of Hyobukyo (a head of the Ministry of War), which was the highest official title he could hold. Because his residence was located in Toin, the book was also called "Heito ki," and some people called it "Jinsha ki" ("Jin" means a man, "sha" means a wheel) after two left-hand radicals of the Chinese characters of his name Nobunori (信範). The diary covers about forty years from 1132 to 1171.

TAIRA no Nobunori came from the Kanmu-Heishi (Taira clan) Takamune line, which was a long line of scholars of the so-called 'the family of diary' and also the family of practical officials, therefore his diary is now an essential historical material to know the activities and ceremonies of the Imperial court in Kyoto and court nobles in the late Heian period. As a household superintendent, Nobunori served FUJIWARA no Tadamichi and FUJIWARA no Motozane of the Sekkan (Regent and Chancellor) family, getting information about the movement of high court nobles, especially Goshirakawa in and the Taira family before and after the Hogen Disturbance, so no record can compete with Nobunori's detailed record about them.

Besides, the original manuscript of "Heihan ki" is characterized by a large quantity of shihaibunsho (records written on the other side of documents during the period when paper was very precious). Nobunori wrote his diary on the other side of case records and administrative documents while he was working as Mandokoro betto (Director of the Administrative Board) and Kurodo gashira (a kind of secretary and archivist to the Emperor), which also came to be important historical materials to understand the inside situation of the Sekkan family and the scope of Kurodo gashira's work.