Why are the ten tribes sometimes called the lost tribes?
The ten tribes are called lost because they went into captivity into Syria around 775 B.C. and never returned as tribes. They remained dispersed and were eventually assimilated into the Middle East, losing their distinct tribal identity and not returning as recognizable tribes.
Les teaches that the ten tribes of the southern kingdom went into captivity into Syria about 775 B.C., and they never really came back as tribes, which is why some people call them the lost tribes. They were already out there in a dispersion. Then about 150 years later the southern two tribes of Judah and Benjamin, which we call Judah, were taken captive all the way to Babylon, and only a few thousand came back after the 70 years. The rest were assimilated into the whole Middle East. Les illustrates this with America's immigrant communities: the old European ethnic background often kept the mother tongue for a generation or two, but after two or three generations they lost it and picked up their adopted language, English. In the same way, the tribes lost their distinct identity through dispersion and assimilation.