Judah, Kingdom of means in the bible: The jealousy among the tribes Ephraim, Judah and Judah caused the division of Solomon’s dominions into two distinct kingdoms during the reign of Rehoboam. Jerusalem was the capital of the southern kingdom, which included Judah’s tribe and the majority of Benjamin. It was more committed to Jehovah worship than the northern kingdom. The southern kingdom was also less vulnerable to attacks from the east and north, so the ultimate power remained with the family of David through the exile. It survived for over 135 years, even after Israel’s fall. The appendix contains a summary of history as well as a list of kings.
(in Bible Dictionary)