In the FUJIWARA no Sumitomo's War, Toshimichi and his father TACHIBANA no Kimiyori, Dazai gon no sochi, countered the attacks of FUJIWARA no Suminori, Sumimoto's brother, who led the invasions of Dazai-fu (local government office in Kyushu region), in Kamachi Castle located on the outskirts of Yanagawa (City) and defeated Suminori.
藤原純友の乱の時に、大宰府に攻め寄せてきた純友の弟の藤原純乗を、父の大宰権帥の橘公頼と柳川市郊外の蒲池城で迎え撃ち、純乗を撃退する。