Based on 20 years of data from demographic registers, the prison register and the criminal case register, we describe the background characteristics of children, adolescents and young adults imprisoned in Norway. We investigate changes in imprisonment rates and types of crime in the period 2000–2019. The chapter describes the situation before incarceration, with a focus on stability in growing up, crime in the family and early contact with the police, before giving a description of the types of offenses and the composition of offenses that resulted in a prison sentence or pre-trial detention. Finally, the chapter examines the completion of the sentence and the proportion who are re-incarcerated after release for the different age groups.