There are some references in scripture which document the history of Yisra'el and Yehudah; our scriptural focus cites the Assyrian invasion of Yisra'el by King Shalmaneser, as given in Melekhim B (II Kings), chapter 17. It is in this account we are told that the citizens of the nation of Yisra'el were exiled and resettled in Chalach, in Chavor, by the Gozan River, and in the cities of Media (Ibid., v.6b).
It is a generally accepted fact that these ten tribes of Yisra'el remained in Chalach and the cities of Media, and did not return to Eretz Yisra'el, for they are recorded in scripture as still remaining there up to the day of its writing (attributed normally to Ezra the Prophet). Multiple sources maintain that the ten tribes comprising the House of Yisra'el (headed by Efra'im) have not yet been reunited with Yehudah, including rabbinical, literary, and historical or archæological sources. Moreover, it is also recorded in scripture that the king of Assyria imported foreigners from Babylonia and other places into the cities of Samaria in place of the Yisra'elis, who had previously lived there (Ibid., v.24).
The House of Yehudah was exiled to Babylon by Nebuchadnezzar through his invasion in or around 3338 (422 bce). About 50 years later, in or around 3390, the exiled Yehudim (Jews) returned to Eretz Yisra'el with permission given by Cyrus (King of Persia) to begin reconstruction of the Holy Temple in Yerushalayim. It was this return and rededication, marked by the leadership of the Maccabees, which is celebrated in the holiday of Chanukkah.
The House of Yehudah remained in Eretz Yisra'el from that point forward, completing the reconstruction of the Holy Temple with authorisation given by Darius of Persia (the son of Esther) in 3408. After the Yehudim returned from Babylonian exile, they encountered the Romans, who invaded Palestine and installed their own governor over the region (which they called Judæa). This puppet throne was occupied for generations by the Herodian dynasty when the Romans finally sacked Yerushalayim in or around 3830 (70 ce). Afterward, the remaining Yehudim, organised by the Zealots, were little more than a single enclave of resistance which made its final stand at the Masada, the last fortified Jewish stronghold, in 3833 (73 ce), when the Romans laid siege to the fortress and wiped out the last vestiges of Yehudi occupation.
The Jewish people as a whole, as they are identified today, are regarded by virtually all authorities of good repute to be descendants of the tribes of Yehudah and possibly Benyamin, as well as some of possible Levitical lineage, though for many who identify themselves as Yehudim (Jews), no confirmed records of their actual tribal lineage exist. The general understanding of this concept is rooted in the notion that the Ten Lost Tribes became absorbed into the respective European, African, or Asian societies into which they emigrated, and that because of this, their identities as Yisra'elis were lost to them.
Then, in 5707 (1947 ce), history was made, when the nation of Israel was created (in political form) to accomodate the multitude of then-newly-homeless Jews who had lived either in Europe or Communist Russia and were suddenly vagrants without a homeland. It is commonly understood that these displaced peoples were various descendants of the tribes of Yehudah and possibly Benyamin, who had been scattered across the earth for nearly 1900 years. Additionally, the Talmud defends this point, making issue of the prophecy that the Ten Lost Tribes were exiled and never returned, having been absorbed by various Gentile societies instead.
In closing, it behoves the reader to bear in mind the notion that prophecy does foretell of the Messianic Age as a period in our future which coincides with a massive reunification between Yosef/Efra'im/Yisra'el and Yehudah. We might also bear in mind that the Rabbinical tradition accepts the idea that a favourable prophecy intended for Yisra'el can be postponed or even revoked by God if Yisra'el turns toward evil.