Siege of Uehara
1541 CE.
Shown on the map at 36.009°, 138.149°.
The siege of Uehara was the first of many steps taken by Takeda Shingen in his bid to seize control of Shinano Province. Uehara Castle had been controlled by Suwa Yorishige before it was taken by Shingen.
Text from the Wikipedia article Siege of Uehara, licensed CC BY-SA 4.0.