This chapter provides an overview of the presence and relevance of childhood traumas in the histories of individuals who have been given a diagnosis of personality and offended. A summary of the impact of childhood traumas, adverse attachments, and adversity and the lack of relational security on individuals’ personality development is described in relation to the diagnostic traits for personality disorders and dynamic risk factors. A service user provides his narrative of the impact of childhood attachment adversity and traumas on his development, mental health, and offending and describes what has been significant in supporting his recovery journey so far. The significant overlap across these areas and the increasing recognition of the need to understand developmental antecedents of individuals’ mental health difficulties and offending are highlighted. Current psychological treatment approaches across forensic services, including those based on a developmental model, are briefly described and the application of Schema Therapy for individuals who have been given a diagnosis of personality disorder and offending is discussed. Overall, the importance of asking individuals what has happened to them and developing a shared understanding of the impact of what happened to them is considered fundamental to supporting development and risk reduction.