The premise of Two House theology is found in the Hebrew Scriptures and primarily focuses on the division of the ancient Kingdom of Israel into two kingdoms, Israel and the Kingdom of Judah (See History of ancient Israel and Judah). The tenets of Two House Theology become controversial and disputed when the ancient reality of the two Israelite kingdoms is applied to modern peoples who are thought to be descendants of the two ancient kingdoms, both Jews and the Ten Lost Tribes of Israel, the latter are believed to have become "the fullness of the nations" Genesis 48:19.