[영문]This paper describes the development of ‘case histories’ from a qualitative longitudinal data set that followed 100 young peoples transitions to adulthood over a ten year period. The paper describes two stages in the analytic process: first, the forging of a case history from a longitudinal archive and second, bringing case histories into conversation with each other. The paper emphasises two aspects of a qualitative longitudinal data set: the longitudinal dimension that privileges the individual case, and the cross sectional dimension that privileges the social and the spatial context. It is argued that both aspects should always be kept in play in analysis. The paper concludes by reflecting on the ethical and practical challenges associated with the case history approach, heightened by the growing demand to archive and share qualitative longitudinal data sets.