Answer:
They migrated from Southern part of West Africa between 2000 BCE and 1000 CE .
Step-by-step explanation:
They migrated from their native land to East Africa due to overpopulation, lack of fertile lands, famine and drought. The region where they settled in East Africa was called The Interlacustrine region. And when they migrated, they caused a few changes in the interlacustrine region such as introduction of metal working skills , introduction of new crops , new culture and language