Genesis 36:15

Duke - A head of a family or tribe.

Dukes of the sons of Esau - The word duke comes from the Latin dux, a captain or leader. The Hebrew אלוף alluph has the same signification; and as it is also the term for a thousand, which is a grand capital or leading number, probably the אלופי alluphey or dukes had this name from being leaders of or captains over a company of one thousand men; just as those among the Greeks called chiliarchs, which signifies the same; and as the Romans called those centurions who were captains over one hundred men, from the Latin word centum, which signifies a hundred. The ducal government was that which prevailed first among the Idumeans, or descendants of Esau. Here fourteen dukes are reckoned to Esau, seven that came of his wife, Adah, four of Bashemath, and three of Aholibamah.

The first dukes of Edom. The Alluph or duke is the head of the tribe among the Edomites, like the Nasi or prince among the Israelites. The ten grandsons of Esau by Adah and Basemath take rank with his three sons by Oholibamah. This favors the presumption that she was his fourth and latest wife. "Duke Corah." This appears to be inserted by a slip of the pen, though it occurs in the Septuagint and Onkelos. It is missing, however, in the Samaritan Pentateuch. It would make twelve dukes, whereas it appears from the closing verses of the chapter that there were only eleven. It is possible, however, that there may have been a Corah descended from Eliphaz who attained to a dukedom; and that Amalek separated himself from the rest of the Edomites and asserted his independence. In the absence of explanatory testimony we must leave this point undecided as we find it.