---Information taken from http://www.scribd.com/doc/46566146/Who-is-Esau-Edom---
"As is it is writted Jacob I have loved but Esau I have hated"-Romans9:13
"Esau was a cunning and decietful man"-Jasher 26:17
Esau was the firstborn son of Isaac and brother to Jacob and when they came of age they inherited their birth right but Esau despised it (Genesis 25:24) and he sold it to Jacob Esau also hated his people and intermixed and married with people outside of his race, he married the daughters of Canaan or canaanites (Genesis 28:6, 36:2) The Heth or Hittites (Genesis 26:34, 27:46, 36:2) The daughters of Ishmael (Genesis 28:9, 36:3) The daughters of Hivities (Genesis 36:2) and had intermarried with the Horites (Genesis 36:19-21: Jasher 30:28)
These intermarriages were a pain to Rebekah and Isaac (Genesis 26:35) the children Esau had with all these people became known as Edomites or Edom (Genesis 36:1,9) He also mixed his Israelite blood in the case of Solomon (1 Kings 11:1).
You could say he had the first true Mixed race Children, you can read more on this topic by reading the book provided in the link at the top.