The development of the concept, causes and management of severe (psychopathic) personality disorder is reviewed against the current background of government concern about the activities of a small group of individuals alleged to be showing the disorder to a dangerous degree. The authors acknowledge the problems involved in 'labelling' the disorder. The term psychopathic has a somewhat chequered history. It did not enter U.K. legislation until the Mental Health Act 1959. To this extent, it is a legal term and does not equate to any exact degree with the clinical descriptions currently in use. However, the term 'psychopathic disorder' will be used as a kind of shorthand for variants in everyday use. It is important to note that in this contribution we are only considering those 'psychopaths' who have come to the attention of the criminal justice and mental health systems. There are also 'psychopaths' who, for a variety of reasons, have not come to official attention and a recent contribution by Board and Fritzon (2005) highlights some interesting common characteristics in business managers and a sample of forensic patients detained in high security establishments.