Historians have long believed that, after the Assyrians destroyed the Northern Kingdom of Israel in 720 BCE, many of its residents fled to the Southern Kingdom of Judah and settled there. The recent discovery of clay seals (technically known as bullae) in Jerusalem—then the Judaean capital—provides evidence of this migration, as Amanda Borschel-Dan writes:
A new cache of First Temple bullae discovered in an excavation at Jerusalem’s City of David shows a mixture of names from the kingdoms of Israel and Judah used on official bureaucratic correspondence. . . The dozens of clay imprints were used on letters and documents which were bound by string and sealed by wet clay pressed with the sender’s mark or name. . . . Among the bullae [one] bears the name “Aḥiav ben Menaḥem” [both names used by kings of Israel and thus thought to be Israelite rather than Judaean]. . . .
According to [the excavation’s] co-director Ortal Chalaf, these Israelite names and other findings point to the possibility that after the destruction of Israel, refugees fled the Kingdom of Israel for the Kingdom of Judah, and settled in Jerusalem. . . . [T]he use of their names on official correspondence shows that these Israelites gained important roles in the Judaean administration.
Read more on Times of Israel: https://www.timesofisrael.com/jerusalem-welcomed-jewish-refugees-2300-years-ago-archaeological-finds-show/