Recognizing that he needed to destroy the Taira navy at Hikoshima, Yoshitsune managed to assemble a force of 840 ships (according to the "Azuma kagami") by calling together support from his allies, including the Watanabe navy of Settsu Province, the Kawano navy of Iyo Province, and the Kumano navy of Kii Province.
彦島の平氏水軍を撃滅すべく、義経は摂津国の渡辺水軍、伊予国の河野水軍、紀伊国の熊野水軍などを味方につけて840艘（『吾妻鏡』）の水軍を編成する。