Sai River (Gifu) in the context of "Nagara River"

The Battles of Kawanakajima (川中島の戦い, Kawanakajima no tatakai) were a series of battles fought in the Sengoku period of Japan between Takeda Shingen of Kai Province and Uesugi Kenshin of Echigo Province from 1553 to 1564. Shingen and Kenshin contested each other for control of the plain of Kawanakajima between the Sai River and Chikuma River in northern Shinano Province, located in the present-day city of Nagano. The battles were triggered after Shingen conquered Shinano, expelling Ogasawara Nagatoki and Murakami Yoshikiyo, who subsequently turned to Kenshin for help.

Five major battles of Kawanakajima occurred: Fuse in 1553, Saigawa in 1555, Uenohara in 1557, Hachimanbara in 1561, and Shiozaki in 1564. The most famous and severe battle was fought on 18 October 1561 in the heart of the Kawanakajima plain, thus being known the Battle of Kawanakajima. The battles were ultimately inconclusive and neither Shingen nor Kenshin established their control over the plain of Kawanakajima.