The 1546 Battle of Odaihara was one of many steps taken by Takeda Shingen, one of Japan's great warlords of the Sengoku period of Japan, in his bid to take over Shinano province. He met the forces of Uesugi Norimasa on the plains of Odaihara, and defeated Uesugi's army while devoting a portion of his own force to the concurrent siege of nearby Shika castle. His victory at Odaihara would grant him hundreds of enemy heads to use for intimidation tactics at Shika.