‘This milestone Research Handbook is a must-read for researchers of the law and policy of European Union citizenship. It interrogates and recasts Union citizenship as a concept, as a vector of rights, and as a social experience; highlighting significant research questions at national, transnational and supranational levels as well as at their intersection. Its timely consideration of the implications for Union citizenship of Brexit and the Covid-19 pandemic and its emphasis on enhancing relationships with the Union’s nearest neighbours have produced a collection that reflects an unsettling era of challenge and change yet remains rooted in deep legal and theoretical foundations.’