First a little bit of background:
Judah, who's name means thanksgiving or praise, was the fourth son born to Jacob and Leah. From birth his family situation was not ideal - Jacob had been tricked into marrying Leah by Leah's father and the Bible said that Jacob hated Leah because of that deception. When Jacob was finally given his true love, Rachel, the gulf between Leah, her kids, and Rachel and her two sons was immense. Jacob, who was also known as a wheeler and dealer, (See Genesis 32:30 for just one example) didn't even bother hiding his favoritism for Rachel's oldest son, Joseph. To the point that finally, in a calculated fit of rage, Leah's sons decided to kill Joseph and rid themselves forever of Jacob's favored son.