MI5 (Military Intelligence, Section 5), [2] officially the Security Service, is the United Kingdom's domestic counter-intelligence and security agency and is part of its intelligence machinery alongside the Secret Intelligence Service (MI6), Government Communications Headquarters (GCHQ), and Defence Intelligence (DI).

MI5's mission is to keep the country safe. For more than a century we have worked to protect the UK from a range of threats, whether it be from terrorism or hostile activity by states.

MI5 and MI6 are both intelligence agencies of the UK government, but there is a crucial difference. MI5 is responsible for protecting UK citizens and interests at home, notably against threats to national security.

The four main agencies are the Secret Intelligence Service (SIS or MI6), the Security Service (MI5), the Government Communications Headquarters (GCHQ) and Defence Intelligence (DI). The agencies are organised under three government departments , the Foreign Office , the Home Office and the Ministry of Defence .

MI5 protects the UK against threats to national security. Threats can range from terrorism to attempts by states to harm people in the UK and undermine our way of life. We carry out...

MI5 exists to protect the UK from threats to our national security, primarily terrorism and threats posed by states. More than 5,000 people work at MI5, bringing together people with lots of...

Jan 15, 2025 · MI5, intelligence agency charged with internal security and domestic counterintelligence activities of the United Kingdom. It is authorized to investigate any person or movement that might threaten the country’s security.

The Security Service, commonly known as MI5, is one of three British intelligence agencies. It is the security agency responsible for counter-intelligence inside the United Kingdom. It gives the government information about hostile activities inside the UK.

Jan 14, 2025 · By the early 1950s they had penetrated all the major institutions of British state security. A newly-released photo of a young Anthony Blunt. Catalogue reference: KV 2/4700 ... The exhibition will mark the first time MI5’s secret history is going on display to the public, featuring original case files, photographs and papers, alongside the ...

Oct 1, 2020 · The two most famous British spy agencies are MI5 and MI6, (both based in London) but there were in fact 15 other Military Intelligence departments which have now either disbanded or were absorbed into MI5 and MI6.