Esau and Jacob were twins, born to Isaac and Rebekah. Esau was the first of the twins to be born. He was covered with red hair, and was called Esau. Some scholars believe that the word Esau means "hairy." Esau became the ancestor of the people of Edom ("red."), which was a country near Israel during ancient times.
Before Esau's birth, the Lord told Rebekah that her older son would serve the younger son (Genesis 25:23). 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.
Esau was born first. But when his twin brother Jacob was being born, Jacob's hand was holding onto Esau's heel. This was taken as a sign that Jacob wanted to be born first. Later in life, Jacob continued to show that he wanted to be his father's heir.
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. (Genesis 25:29-34.)
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.
In the New Testament passage of Hebrews 12:16, Esau is described as immoral and unreligious. Paul, in Romans 9:10-13, indicates that God had chosen Jacob to be the heir to the promises that he had made to his grandfather, Abraham. Details about Esau can be found in Genesis chapters 25-36.