The present volume is based on an international summer school on migration, asylum and refugee law that took place in Barcelona. In the spirit of intergenerational academic exchange, students, young researchers, and established experts engage in interdisciplinary discussions on fundamental questions of migration law and migration policy, which have become more virulent than ever since the refugee protection crisis of 2015. European, human rights and international law aspects are supplemented by national perspectives from Belgium, Bulgaria, the Federal Republic of Germany, Italy, Spain, Turkey and the United Kingdom. The entire project sees itself as a laboratory for the exchange of ideas on how modern migration societies can orient themselves towards a sustainable future.