When the sixth head of the family Hirosue ISHIKAWA heard that MINAMOTO no Yoritomo raised an army to defeat the Taira family in Izu, he dispatched an army headed by his uncle Mitsuharu to Kamakura in 1183.
第6代石川広季は、伊豆で源頼朝が平家討伐の兵を挙げたことを知り、寿永2年（1183年）、伯父光治率いる軍を鎌倉に送る。