Peter Tyrer is Emeritus Professor of Community Psychiatry in the Centre for Psychiatry in the Department of Medicine at Imperial College, having previously been head of department and a professor at Imperial College since 1991. He has been interested in the common mental disorders, particularly personality disorder, since a medical student 50 years ago when he first developed a classification of his teachers. Since then he has been involved in both clinical and research practice to improve awareness and the utility of these most commonly experienced disorders in clinical practice. He has chaired NICE guideline groups for borderline personality disorder, substance misuse and psychosis, and management of imminent aggression for the Department of Health in England, has written 39 books, including three on personality disorder, and over 500 original articles. He was the Editor of the British Journal of Psychiatry between 2003 and 2013 and is on the editorial boards of six other journals. He is also Chair of the World Health Organisation’s ICD-11 Revision Group for the Classification of Personality Disorder, which will introduce a radical change to the existing classification very shortly.