Kamakura shogunate
The Bunji authorization expands Yoritomo's policing and revenue powers
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Original prompt & settings (JSON) ↗A manhunt for his own brother gave Minamoto no Yoritomo the legal opening to plant agents across western Japan — and to tax rice for their upkeep.
A manhunt and a petition
In the eleventh lunar month of Bunji 1 — December 1185 in modern Japanese government chronologies — Yoritomo's envoy Hōjō Tokimasa negotiated with the Kyoto court for authority to pursue Minamoto no Yoshitsune and Minamoto no Yukiie and to exercise new powers in western Japan. How much of that was the real point turns on provenance: the contemporary rationale on record concerns pursuit and policing — suppressing rebels without repeatedly dispatching eastern warriors across the country — while a later account specifically presents Yoshitsune's pursuit as the arrangement's avowed justification.
The court, operating under the dominant influence of Retired Emperor Go-Shirakawa, granted more than a pursuit warrant. The contemporary diary Gyokuyō records approval on the twenty-ninth day of that month for Yoritomo's side to deploy provincial agents and collect provisions.
Five shō from every tan
The authorization permitted a commissariat levy on public and private estates alike: five shō of rice per tan of land. The Kanagawa prefectural archive equates one shō to 1.8 litres and one tan to 993 square metres.
The levy and the authority to deploy provincial agents helped extend the Kamakura regime's reach beyond its eastern base.
Not a shogunate in one stroke
Yoritomo did not receive the title sei-i taishōgun until 1192, and some of the 1185 powers were curtailed the following year. The court kept its provincial governors, and estate owners, temples and court institutions continued alongside the new Kamakura appointees.
The later chronicle Azuma Kagami describes the grant using nationwide shugo and jitō, but research based on contemporary evidence argues the request chiefly concerned temporary provincial pursuit powers. Historians propose 1180, 1183, 1185, 1190 and 1192 as foundation dates for the bakufu.
Sources
Researched 23 Aug 2026 5 sources 3 audit passes, 1 issue open Date disputed
How this was checked
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Date disputed. Sources disagree about when this happened.
What the sources leave uncertain
- Japanese records give Bunji 1, eleventh month, twenty-ninth day. Modern English summaries disagree or silently mix lunar dates with Western dates, so December 1185 is safer than asserting a particular Gregorian day.
- The exact institutional content is disputed. The later Azuma Kagami describes nationwide shugo and jitō, while research based on contemporary evidence argues that the request chiefly concerned temporary sōtsuibushi or provincial pursuit powers.
- Historians propose several foundation dates for the Kamakura bakufu, including 1180, 1183, 1185, 1190 and 1192; calling this decree the uncontested creation of Japan's 'first shogunate' is anachronistically tidy.