The Metropolitan Police of Greater London is organised into four main directorates, each with differing responsibilities. These are Frontline Policing (formerly Territorial Policing), Met Operations (formerly Specialist Crime & Operations), Specialist Operations, Professionalism and six civilian staffed support departments under the umbrella of Met Headquarters. Each is overseen by an Assistant Commissioner, or in the case of a support department a director of police staff which is the equivalent civilian grade.