Because the Isshiki clan fought with the Western army in the Onin War, their position as Shugo was for a period of time lost to the Takeda clan of neighboring Wakasa Province and, moreover, during the Sengoku period, power was forcibly taken by the Shugodai (Deputy Governor) Nobunaga clan, which led to a decline in fortunes.
一色氏は応仁の乱において西軍に与したため、守護職を一時隣国の若狭国武田氏に奪われるなど没落し、さらに戦国時代には守護代延永氏の下克上により衰退していた。