Drawing on interviews with over ninety former participants in the Non-Stop Picket of the South African Embassy and extensive archival research using previously unstudied documents, this book offers new insights to the study of social movements and young people’s lives. It theorises solidarity and the processes of adolescent development as social practices to provide a theoretically-informed, argument-led analysis of how young activists build and practice solidarity. will be of interest to geographers, historians and a wide range of other social scientists concerned with the historical geography of the international anti-apartheid movement, social movement studies, contemporary British history, and young people’s activism and geopolitical agency.