The police role in countering terrorism is focused at the nexus where the crime and criminality referred to as 'terrorism' adversely impact on public safety and national security. Exactly what the responsibilities and main functions of the police within each country are in respect to counterterrorism depends on two things. First, how police and policing are carried out generally, and second, the current threat from terrorism and its history. The United Kingdom also suffered a number of attacks inspired by the ideologies of anarchism and nihilism from 1892 onwards, and more than one significant plot was disrupted. By the end of the twentieth century, the threat from terrorism and the need to counter it were an integral part of the responsibilities of national and urban police forces across Europe and beyond. The chapter examines how the police are organised and tasked to counter terrorism in all its main manifestations.