They became antagonistic to the Deputy Shugo Nagao clan and during Fusatada UESUGI's time, they defeated the Nagao clan, becoming the dominant power in what was their heyday.
守護代の長尾氏と対立するようになり、上杉房定の代には長尾氏を抑え優勢となり全盛期を築き上げた。