This chapter investigates sociodemographic and environmental factors associated with the relocation and settlement of Karelian evacuees during and after the Second World War. During the war over 400,000 people were forcibly displaced from the Karelia region in Finland and evacuated to western Finland. Soon after the start of the Continuation War (1941–1944) Finland recaptured Karelia from the Soviet Union and these refugees had the opportunity to return to Karelia, approximately 70% did so. Using the digitised MiKARELIA database, the movements of 59,477 Karelian evacuees and their decisions to return to Karelia or stay in western Finland during the Continuation War and the factors associated with their return are analysed. In addition, the post-war movements of these evacuees are investigated to shed light on how Karelians assimilated. The results of this study provide new information on many factors known to have affected the settlement and assimilation of Karelian evacuees during and immediately after the Second World War.