In order to grasp the complexity of migration trends in Europe it is important, given the limitations of the available statistics, to look at the wider issue, breaking it down into four separate elements: 1. the migration flows affecting Council of Europe member states in recent decades, distinguishing between migration between member states and migration flows with other parts of the world; 2. the reasons for migration, with particular reference to illegal migration or asylum; 3. the socio-demographic features of migrant populations, described with reference to the data on migrant “stocks” (foreign populations in each of the member states); 4. the expected trends for the coming years, based on demographic processes in the various member states and possible sources of migrants.