Sighed: Ichiyūsai Kuniyoshi ga
Artist's seal: kiri
Publisher: Enshūya Hikobei
(Marks 055 - seal 22-005)
Related links: Museum of Fine Arts, Boston; British Museum; Honolulu Museum of Art; Harvard Museum of Arts; Keio University Library; Waseda University - right panel; Waseda University - middle panel; Waseda University - left panel; Tokyo Fuji Art Museum - the outer prints of the earlier ca. 1831 triptych; Manggha Centre of Japanese Art and Technology, Krakow - badly damaged left panel; Google maps - Seta River, then called Ujigawa - we don't know the exact location of the battle yet, but will try to find out;
"The Minamoto generals Kajiwara (left), Sasaki Takatsuna (centre) and Hatakayama Shigetada (right) are depicted crossing the Uji river on horseback during their attack on the army of Kiso [Minamoto] Yoshinaka in 1184..."
Quoted from: Heroes and Ghosts: Japanese Prints by Kuniyoshi 1797-1861 by Robert Schaap, p. 98, #82. This is accompanied by a color reproduction.
The curatorial files at the British Museum say: "Kajiwara Kagesue on black horse, with Sasaki Takatsuna [佐々木高綱: 1160-1214] on white horse, and arrows from Yoshinaka's troops."
Kuniyoshi created an earlier triptych of this same subject in 1831-32.
Sasaki Takatsuna was the son of Sasaki Hideyoshi (1112-84) who died in the struggle against Yoshinaka. Takatsuna was made the governor of Bizen and later of Aki. After he shaved his name he took the name Ryōchi and retired to Kōya-san.
There is actually a word for the act of riding a horse across a river. It is suiba (水馬). It is also the name of the stirrup used in such a venture. Those stirrups are pierced in such a way as to let the water drain through, thus helping the foot to dry and to keep it from festering.