This phrase is used here to mark the beginning of a new part of the story. If your language has a way for doing this, you could consider using it here.
Here the words "all Israel" refer specifically to the people of the tribes of Judah and Benjamin, over which Rehoboam was king. The verb may be supplied from the previous phrase. AT: "all the Israelite people whom he ruled also abandoned the law of Yahweh" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-ellipsis]])