The idea for this edited collection arose out of a series of interdisciplinary workshops entitled ‘Gender and Migration in 21st Century Europe’ hosted jointly by the Migration Unit and the Feminist Legal Research Unit at the University of Liverpool between October 2006 and April 2007. The same title is adopted for this collection which draws on the presentations and discussions that took place during the workshops coupled with additional invited contributions from notable scholars in the field. In referring to ‘gender’ the aim is to explore how social, economic, legal, political and cultural processes implied by migration govern and reinforce relations between the sexes – not just between men and women, but between female and male children, and between girls and women. Our interpretation of ‘migration’ is also broad to encompass a range of geographical, economic and personal trajectories into and within Europe as well as the emergence and effectiveness of new regulatory mechanisms to address issues of ‘forced’ migration (notably trafficking), cross-national family breakdown and employment migration in an expanding European Union.