A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
gen 36:1POSTERITY OF ESAU. (Gen. 36:1-43)
these are the generations--history of the leading men and events (compare Gen 2:4).
Esau who is Edom--A name applied to him in reference to the peculiar color of his skin at birth [Gen 25:25], rendered more significant by his inordinate craving for the red pottage [Gen 25:30], and also by the fierce sanguinary character of his descendants (compare Eze 25:12; Oba 1:10).
gen 36:2Esau took his wives of the daughters of Canaan--There were three, mentioned under different names; for it is evident that Bashemath is the same as Mahalath (Gen 28:9), since they both stand in the relation of daughter to Ishmael and sister to Nebajoth; and hence it may be inferred that Adah is the same as Judith, Aholibamah as Bathsemath (Gen 26:34). It was not unusual for women, in that early age, to have two names, as Sarai was also Iscah [Gen 11:29]; and this is the more probable in the case of Esau's wives, who of course would have to take new names when they went from Canaan to settle in mount Seir.
gen 36:6Esau . . . went into the country from the face of his brother Jacob--literally, "a country," without any certain prospect of a settlement. The design of this historical sketch of Esau and his family is to show how the promise (Gen 27:39-40) was fulfilled. In temporal prosperity he far exceeds his brother; and it is remarkable that, in the overruling providence of God, the vast increase of his worldly substance was the occasion of his leaving Canaan and thus making way for the return of Jacob.
gen 36:8Thus dwelt Esau in mount Seir--This was divinely assigned as his possession (Jos 24:4; Deu 2:5).
gen 36:15dukes--The Edomites, like the Israelites, were divided into tribes, which took their names from his sons. The head of each tribe was called by a term which in our version is rendered "duke"--not of the high rank and wealth of a British peer, but like the sheiks or emirs of the modern East, or the chieftains of highland clans. Fourteen are mentioned who flourished contemporaneously.
gen 36:20Sons of Seir, the Horite--native dukes, who were incorporated with those of the Edomite race.
gen 36:24This was that Anah that found the mules in the wilderness--The word "mules" is, in several ancient versions, rendered "water springs"; and this discovery of some remarkable fountain was sufficient, among a wandering or pastoral people, to entitle him to such a distinguishing notice.
gen 36:31kings of Edom--The royal power was not built on the ruins of the dukedoms, but existed at the same time.
gen 36:40Recapitulation of the dukes according to their residences.