During the Kamakura period after the decline of the Taira clan government, there were no official diplomatic relations between Japan and the Sung dynasty, but the Kamakura bakufu (Japanese feudal government headed by a shogun) allowed private trade and in 1185 chinzei bugyo (a magistrate of Kyushu region) established in Kyushu governed Hakata and sent bakufu-controlled commercial ships to Sung.
平氏政権滅亡後の鎌倉時代には日宋間の正式な国交はなかったが、鎌倉幕府は民間貿易を認め、文治元年（1185年）に九州に設けられた鎮西奉行は、博多を統治して幕府からの御用商船を宋へむけて派遣することとした。