International migration suddenly became a key issue in international politics at the beginning of the 1990s, when the breakdown of the bi-polar power constellation of the Cold War seemed to have opened the floodgates for vast new population flows. Right-wing politicians and sensationalist media conjured up images of welfare states being ‘swamped’ and national identities being undermined by mass movements of impoverished people from East to West and South to North. Governments responded with tight border restrictions and international control measures such as the Schengen Agreement. In the meantime, exaggerated fears have died down, but issues of migration regulation and the effects of migration on both sending and receiving societies remain prominent in political and academic discourse. It is now widely recognized that cross-border population mobility is inextricably linked to the other flows that constitute globalization, and that migration is one of the key forces of social transformation in the contemporary world. This makes it vital to understand the causes and characteristics of international migration as well as the processes of settlement and societal change that arise from it.