Judah was, according to the Book of Genesis, the fourth of the six sons of Jacob and Leah and the founder of the Tribe of Judah of the Israelites. By extension, he is indirectly the eponym of the Kingdom of Judah, the land of Judea, and the word Jew.
According to the narrative in Genesis, Judah alongside Tamar is a patrilineal ancestor of the Davidic line.