In the Tokugawa clan pedigree sitting at the top of the family tree is the Egawa clan branch (decedents of Nitta clan of the Seiwa-Genji) and accordingly the original family name is said to have been either; the Minamoto surname or Minamoto no Ason.
徳川氏の系譜は、系図上は清和源氏の新田氏の支流得川氏の末裔と位置付けられており、従って本姓は源姓であり、源朝臣という。