Sobuji-rei was an edict that prohibited duels between daimyo (feudal lords), issued by Hideyoshi TOYOTOMI. In the discipline of history, Sobuji-rei is sometimes referred to as one of Toyotomi heiwa-rei (Toyotomi's peace edicts), a series of edicts to control personal conflicts such as Katanagari-rei (an edict prohibiting peasants from possessing arms), Kaijo kaizokusen kinshi-rei (an edict outlawing pirates), and kenka teishi-rei (an edict prohibiting fights and violence with weapons). Conflicts concerning territories between daimyo were dealt with by the Toyotomi administration as a supreme arbitrator, and it was decreed that any daimyo who acts against the edict was to be severely punished.
It was issued in November 1585 in the Kyushu region, and was issued in December 1587 in the Kanto and Ou regions.
The issue of sobuji-rei gave justification to Hideyoshi's suppression of Kyushu and Odawara. Especially in the case of the Gohojo clan, it led to seppuku (suicide by disembowelment) of Ujimasa HOJO, and it also caused Masamune DATE, Harumasa NANBU, and Yoshiaki MOGAMI to return to their allegiance to Hideyoshi (Ou shioki or the punishment of Ou). It also worked to show the status of Hideyoshi as Kanpaku (the chief adviser to the Emperor); that is to say, sobuji-rei enabled Hideyoshi's project of Tenkatoitsu (the unification of the whole country), and it also acted as the principle of control for the Toyotomi administration.