Judah was a son of Jacob and last born son of Leah as described in Genesis. He was a Patriarch, one of the original ancestors of Israel and the tribe that descended from him. While not much is recorded about Judah there is much more information about him compared to the majority of his brothers.
Judah is most known for his legacy through the Tribe of Judah, Nation of Judah and later Judea. Judah is well known for his relationship with Joseph and Benjamin, as well as his sexually immorality with his daughter-in-law; whom he believed to be a prostitute.
Judah was born to Jacob's first, but least favored wife Leah. Jacob wanted the daughter of Laban, Rachel's hand in marriage and paid the bride price of seven years of work. While he was promised Rachel he was instead given her older sister Leah. After another seven years work he gained Rachel as his wife. Leah remained the least favored wife. In remorse, God allowed Leah to bear children while Rachel remained barren.
After Leah bore three children to Jacob she had one last son named Judah. She gave him this name, because she would praise God for all the children she had received.
Plot Against Joseph
Along with his brothers, Judah developed a hatred of their father's favorite child, Joseph. After Joseph was given a family tunic and had dreams claiming his brothers would one day worship him the brothers became extremely jealous.
Once Judah and his brothers (except Joseph) were shepherding their father's flocks near Shechem. Afterwards they went to the flocks kept near Dothan. When they saw that Joseph had been sent to check up on them, they conspired to kill him. Only Reuben did not go along with the plan to kill their brother. Judah and his brothers threw Joseph into a cistern, but Judah suggested selling him to Ishmaelite (also called Midianite) merchants.
His own family
Marriage and Children
Then Judah and his brothers led their father to believe Joseph was dead and he mourned. Shortly thereafter he went to stay in the city of Adullam with Hirah. In Adullam Judah met the daughter of a Canaanite, married her and slept with her. Nine months later Judah had his first son born to him and he was named Er. Later Judah slept with his wife twice more and had a son named Onan and Shelah.