Lost Tribes of Israel
This refers to the ten northern tribes of Israel who were taken captive, (with many deported to Assyria) about 722 BC, though some of them had previously reunited with Judah, hence it’s later prominence (2 Kgs 17:6; 2 Chr 34:6-9). Later Judah (the southern two tribes) was also conquered and many people lost their true identity when under captivity (2 Kgs 25:1). After several decades many Israelites, from all 12 tribes, were allowed to return to their homeland to rebuild the temple in Jerusalem (Ezra 1:1-5). Jesus mentions the 12 tribes as does James who addresses his epistle “To the 12 tribes scattered among the nations” (Lk 22:30; Jas 1:1).
Following the siege of Jerusalem by the Romans, in A.D.70, Jews were scattered worldwide but increasingly many Jewish people are returning to settle in their ancestral homeland. In spite of this dispersion and intermarrying with other nations descendants of these tribes are still in existence today and during the millennium (the Messianic Kingdom) God will call forth witnesses from each of the 12 tribes who remain faithful to Him (Rev 7:3-8).
See also: British Israelism, Israel, Messianic Jews, millennium, tribe/tribes.