But after the death of Solomon, national Israel was partitioned. Judah and Benjamin became formally known as "the Kingdom of Judah." The rest, i.e., the Ten Tribes, aka the Northern Kingdom, claimed the name "Kingdom of Israel" for themselves.
(Example: Ahab was King of Israel but not King of Judah.)
The upshot of this is that after the death of David's son--the King of all Israel--the Jews wound up separated from Israel.
Think of the prophetic/eschatological implications of this! It's especially interesting when we remember that the Ten Tribes, i.e, Israel, wound up in the Gentile nations!
(John realized this was significant when he heard the words of the High Priest about the looming death of Jesus Christ! John realized that the whole situation of the Diaspora was actually a weird typological picture in which the odd circumstances of [and changes involving] the elect nation of Israel were depicting a soteriological election involving a spiritual Israel of Gentiles!
In other words, the significance of Israel actually changed with the dispensational shift which occurred after the Cross-work of Christ. The Church became the spiritual entity in which the promises to national Israel were fulfilled. This agrees with what Paul says about the "seeds of Abraham" in Galatians! [It also fits Paul's statement that the Christians are actually the True Jews--i.e., the true heirs of all that Judaism itself signified!])