He also used "Ishikawa clan" as his surname due to the fact that, since the time of MINAMOTO no Yorinobu, the founder of the Kawachi-Genji (Minamoto clan), the clan manor had been the Ishikawa Manor in Kawachi Province (which today would be located in Habikino City, Osaka Prefecture).
河内源氏の祖の源頼信以来の河内国石川荘（大阪府羽曳野市）に拠って石川氏を苗字とした。