MI5, MI6 and GCHQ

MI5, MI6, and GCHQ are the primary intelligence and security agencies of the United Kingdom, specialising in domestic security, foreign intelligence collection, and signals intelligence alongside cybersecurity. Operating under the authority of the British government, these organisations work to protect national security, safeguard economic interests, and counter hostile threats. They are known for their clandestine capabilities, advanced technical expertise, and extensive global intelligence partnerships. Together, they combine human espionage, technical surveillance, and cyber defence to disrupt terrorism, counter foreign espionage, and support national strategic priorities.