Counter Terrorism Command (CTC) or SO15 is a Specialist Operations branch within London's Metropolitan Police Service. The Counter Terrorism Command was established as a result of the merging of the Anti-Terrorist Branch (SO13) and Special Branch (SO12) in October 2006, bringing together intelligence, operations, and investigative functions to form a single command. CTC has over 1,500 police officers and staff, and a number of investigators based overseas and also hosts the National Counter Terrorism Policing Network headquarters.