In 1536, Nagamasa KIZAWA, a chief retainer of the Hatakeyama clan and shugodai (deputy military governor) of half of Kawachi Province and five counties of Yamashiro Province built a castle on the Mt. Shigi and conceived a plot to conquer Yamato Province.
天文(元号)5年（1536年）、畠山氏重臣で河内半国・山城下五郡守護代の木沢長政が信貴山に城を構え、大和攻略に乗り出す。