From the end of the Kamakura period to the beginning of the period of the Northern and Southern Courts (Japan), the clan moved from Nanjo in Sahashinosho, Echigo Province (present Kashiwazaki City, Niigata Prefecture) to the Yoshidakoriyama-jo Castle in Takada County (present Akitakata City, Hiroshima Prefecture), and developed their power as assuming the position of kokujin ryoshu (local samurai lord), then became a Sengoku daimyo (Japanese territorial lord in the Sengoku period) in the Sengoku Period (Period of Warring States), the clan eventually grew to be the most powerful one in the Chugoku region.
鎌倉時代末期から南北朝時代(日本)初期にかけて、越後国佐橋庄南条（現在の新潟県柏崎市）から高田郡吉田郡山城（現在の広島県安芸高田市）へ移った後に国人領主として成長し、戦国時代(日本)には国人領主から戦国大名への脱皮を遂げ、ついには中国地方最大の勢力となる。