Esau was the older brother of Jacob, and the first son of Isaac and Rebekah. He sold his birthright to his younger brother's (most likely in a jokingly or unserious matter) after he was hungry for his soup.
At one point Isaac was childless with his wife Rebekah and so he prayed for her. God granted the couple's wish, and promised children to be borne unto them. While in the womb the babies fought with each other.
Before Esau's birth, God told Rebekah that her older son would serve the younger son and that two separate nations would be born from her. This was the reason for the fighting amongst the two in the womb. This was an unusual concept in ancient times because the oldest son was regarded as the heir of the father's wealth, power and authority.
Selling his birthright
One day, Esau returned from an unsuccessful hunting trip and was famished. He saw that Jacob had been cooking food and he asked for a serving. Jacob asked him if he would be willing to sell his rights as the first-born son in exchange for a bowl of food. Esau agreed.)
Regardless of whether Esau was being serious or flippant in selling off his birthright, Jacob sought to make good on the deal and, with his mother's help, tricked his aging father into giving Jacob the blessing that traditionally would been reserved for the first-born.
After Jacob had gotten the blessing from his father, Esau vowed to kill Jacob. To protect Jacob, his mother arranged for him to live with her relatives in Haran. Jacob lived in Haran for about 20 years, working for his uncle, Laban. When Jacob returned home, his brother, Esau, who now had wealth and a 400-man army, forgave Jacob.
Esau married Hittite women, against his parents wishes. He also married two Ishmaelite women. One of them was Mahalath, the daughter of Ishmael, Abraham's son. After Isaac died, Esau took his wives, his children, his servants and his cattle and moved away from his brother to Mount Seir.
Esau is described as immoral He is indicated not to be the heir of Issac but rather his brother Jacob. It is described that Esau was "hated by God" and shows that he did not have a faith in God. Before his birth, God foresees that from Esau's descendants would become subject to Israel at one point. Esau is often used as a synonym to refer to the nation of Edom, particularly in the book of Jeremiah.