This paper studies the employment effects of one of the largest forced population movements in history, the influx of millions of German expellees to West Germany after World War II. This episode of forced mass migration provides a unique setting to study the causal effects of immigration. Expellees were not selected on the basis of skills or labor market prospects and, as ethnic Germans, were close substitutes to native West Germans. Expellee inflows substantially reduced native employment. The displacement effect was, however, highly non-linear and limited to labor market segments with very high inflow rates.