Forced migration means the involuntary movement of people from their region or country of origin to another region or country. The question of what can be considered voluntary or involuntary migration is controversial. Involuntary migration can occur due to expulsion or forced resettlement, “ethnic cleansing”, war or violent conflict as well as poverty and increasingly also changes of climate. The deportation and forced displacement of people by the National Socialists as well as the flight and expulsion of “ethnic Germans” in the former Eastern German territories after the Second World War are only some examples of state-led migration control.