Are you sure you do not mean gramps was a Hebrew because on the whole the Term Jew is usually falsely used as a real Jew would come from Judea or a descendant of the same and these were only One of the Tribes of Israel, and as a general rule there are not so many real Jews, and many many that are falsely called Jews as these Hussars that adopted the name Jew to escape persecution deserved at that! they even memorized and practiced the religious aspects of Hebrews to blend in, and so the term Judaism is a borderline Oxymoron!.