She references historically famous backstabbers in a song about liars. Cain murdered his brother Abel, Brutus murdered his friend emperor Caesar in order to himself get his power, and Judas betrayed Jesus to the Romans.
Soweto is an abbreviation for the SOuth WEstern TOwnship near the city of Johannesburg in South Africa. In 1976, the government tried to enforce African education (instead of English), which lead to marches of violent protests by the citizens
Menelik II was an Ethiopian leader who in the late 1800s brought a lot of technology and modernization to his country (civilization). Some historians consider Menelik II one of the most powerful black men in history.