The Rokkaku clan is one of four branch families of the Sasaki clan called Omi-Genji (Omi Gen clan), and had ruled the entire area of Minami Omi as the shugo (guard) since the Kamakura era.
近江源氏と呼ばれた佐々木氏の四家に分かれた家のうちの一つで、鎌倉時代より守護として南近江一帯を支配していた。