Battle of Sezawa
1542 CE.
Shown on the map at 35.896°, 138.245°.
The Battle of Sezawa was the first major battle fought by Takeda Shingen in his campaign to gain control of Shinano Province. He took on and defeated a coalition of Shinano daimyō including the leaders of the Suwa, Ogasawara and Murakami clans.
Text from the Wikipedia article Battle of Sezawa, licensed CC BY-SA 4.0.