According to the shrine's biography, Masako HOJO was granted with shingo (literally "shrine name" which is the title given to a Shinto shrine) of Shirahata Daimyojin (the great deity of the white flag) and she founded the shrine in 1200.
社伝によると北条政子が朝廷より白旗大明神の神号を賜り正治2年（1200年）に創建したされる。