Battle of Akatsuka
1552 CE.
Shown on the map at 35.079°, 136.951°.
Battle of Akatsuka (or Akazuka, May 10, 1552) was the first recorded battle of the young Oda Nobunaga in his struggle to unite the province of Owari, against one of the former vassals of his late father (Oda Nobuhide, died in 1551), who switched his allegiance to the powerful Imagawa clan of Suruga province.
Text from the Wikipedia article Battle of Akatsuka, licensed CC BY-SA 4.0.