For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
I believe that Ishmael's descendants were the start of the Arab Nations. The 12 princes are his son's. Their names listed in the order of there birth are: Nebaioth, Kedar, Adbeel, Mibsam, Mishma, Dumah, Massa, Hadad, Tema, Jetur, Naphish and Kedemah.
Genesis 25:18 says: And they lived in hostility toward all their brothers.