一本御書所は、平安宮(内裏)の東側、侍従所の南にあった。
平安時代に、世に流布している書籍を、別に一本(一部)ずつ書写して保管管理しておく役所だった。また、「一本書(1冊のみの稀覯本、孤本、貴重文書)」を納めさせ保管していたともいう。職員には、公卿などを任じた別当、預(あずかり)、書手(しょしゅ)などがいた。
平安時代中期、948年3月に「本宮御書所預、書手等便補一本御書所何」と記されている。(『貞信公記』)。964年10月13日条に、一本御書所で清書した222巻を、大蔵省の野御倉に遷納したと記されている。(『日本紀略』)。平安時代後期の第74代・鳥羽天皇(在位:1107-1123)、第75代・崇徳天皇(在位:1123-1141)が度々行幸した。1159年の平治の乱の際に公卿・藤原信頼らが後白河院(第77代)を一本御書所に押し込めたという。
The Ichibon Goshodokoro was located on the east side of the Heian Palace (Dairi), south of the Jijūsho.
In the Heian period, it was an office responsible for transcribing and managing one copy (one volume) of the books circulating in society. It is also said that it stored rare and precious documents, referred to as "Ichibonsho" (unique books, solitary books, valuable documents). The staff included bettō (supervisors) appointed from among the court nobles, azukari (custodians), and shoshu (scribes).
In the mid-Heian period, it is recorded in March 948 that "Honmiya Goshodokoro no azukari and shoshu were supplemented by Ichibon Goshodokoro." (from the "Teishin Kōki"). On October 13, 964, it is noted that 222 volumes copied at the Ichibon Goshodokoro were transferred to the Nomikura of the Ōkura-shō (Ministry of the Treasury) (from the "Nihongi Ryaku"). During the late Heian period, Emperor Toba (74th emperor, reigned 1107-1123) and Emperor Sutoku (75th emperor, reigned 1123-1141) visited frequently. During the Heiji Rebellion of 1159, the court noble Fujiwara no Nobuyori and others confined Emperor Go-Shirakawa (77th emperor) in the Ichibon Goshodokoro.
