The was a battle that took place along the banks of the Nagara River
, Gifu Prefecture
, in April 1556. It was a battle between Saitō Dōsan
and his son, Saitō Yoshitatsu
In 1542, Dōsan became the representative of the Toki clan
and ruled over Mino Province
as such. He had originally planned on passing his power onto Yoshitatsu, but in 1555, he started thinking of passing it on to one of his other sons, Kiheiji (喜平次).
Yoshitatsu, who was living in Sagiyama Castle
at the time, heard of his father's plans and, in 1556, killed his two brothers in the family residence on Mount Inaba
, starting the intrafamily skirmish. Yoshitatsu was able to gain the support of a large portion of the family's soldiers, gathering approximately 17,500 men. Dōsan, on the other hand, was only able to amass around 2,700 soldiers.
Yoshitatsu handily won the battle, which ended in Dōsan's death. Oda Nobunaga had sent in troops to support Dōsan, but they did not reach the battle in time to offer any help.