According to the 'Kiso keizu' (The Genealogical table of the Kiso family) of Kiso, Shinano Province, the third son of Yoshinaka, Yoshimoto, is said to have been the first head of the Kiso family.
信濃国木曽の「木曽系図」では、義仲の三男義基（よしもと）を初代とする。