Judah is the fourth son of the patriarch Jacob and his first wife, Leah: his full brothers are Reuben, Simeon and Levi (all older), and Issachar and Zebulun (younger), and he has one full sister, Dinah. Through his father, he also has six half-brothers: Dan and Naphtali (whose mother is Bilhah), Gad and Asher (whose mother is Zilpah), and Joseph and Benjamin (whose mother is Rachel).
Following his birth, Judah's next appearance is in Gen 37, when he and his brothers cast Joseph into a pit out of jealousy after Joseph approaches them, flaunting a coat of many colors, while they are working in the field. It is Judah who spots a caravan of Ishmaelites coming towards them on its way to Egypt and suggests that Joseph be sold to the Ishmaelites rather than killed.
–Wikipedia