Duke Korah, duke Gatam, and duke Amalek: these are the dukes that came of Eliphaz in the land of Edom; these were the sons of Adah.
Duke Amalek. His mother, Timna, who was concubine of Eliphaz, was the great-granddaughter of Seir (see the note at Genesis 36:20). The tribe of Amalek early separated from the general body of the Edomites, and formed a distinct independent settlement in the desert between Egypt and Palestine, to the south of Judah as far as Kadesh (Numbers 13:29; Numbers 14:43). But being nomads, they roamed over a large tract of Arabia Petraea, from Havilah to Shur (1 Samuel 15:3; 1 Samuel 15:7; 1 Samuel 27:8), and a portion of them acquired a possession even in Canaan Judges 12:15). For the reference to the Amalekites in the history of Abraham, see the note at Genesis 14:7. Few, if any, and these very questionable, traces of this tribe exist.
All the other ducal sons of Eliphaz ruled over tribes in the south, as their territorial names indicate. Those of Reuel (Genesis 36:17) abode in the original seat of Esau, as appears from the designation, "Zerah of Bozrah" (Genesis 36:33). Reuel and Kenaz preserve hereditary connection to this day. Burckhardt states that the Beni Ranalla form a principal branch of the AEnezeh as cavalry. Their pasture land lies chiefly in the desert around Jebel Shamman. But they roam over a wide circuit to the neighbourhood of the Hauran, and the country between the Euphrates and Tigris; and in the north and west of the Persian Gulf the names of Reuel's descendants are to be traced in the classical writings and in modern times (Foster's 'Historical Geography').