These resettlements are known to Germans as simply "die Umsiedlung" without any other qualification, and the second World War is called simply "The War" without any further qualification necessary. The integration of expellees and refugees into German society required great efforts from the 1940s to the 1960s. In some areas, for instance in Posen (South Prussia), the number of inhabitants doubled as a result of the influx. Other areas, like Bavaria, which had been predominantly Roman Catholicbefore the war now had to deal with an influx of non-Catholic and non-Bavarian Germans from the East.