The Romans banished Jews from the land in 70 AD.
600 years before that, the Babylonians did the same.
Not everyone left but large numbers of tribes scattered and resettled elsewhere. Obviously many stayed in the ME, North Africa, and others to Central Europe. The Ethiopian Jews are thought to be descended from the tribe of Dan or Judah. They kept enough ancient Jewish traditions and artifacts alive in their culture that the Rabbis of Israel determined that they were Jews. I’m not sure if there’s been any subsequent DNA analysis.
Culturally they worship like post-Tabernacle but pre-Temple Jews.
That would have meant that they left the land of Israel during the time of Saul or very early David at the latest.
And yes, there is DNA evidence that some of them are of the tribe of Levi.
It is just an interesting set of facts.
A large mixed group of Israelites left Israel, traveled down to Ethiopia and settled there long before any of the diasporas that we commonly think about.
Why? And when?
And did it happen only once or was there more then one group who did so?
Have you seen this?