Secret Intelligence Service

The Secret Intelligence Service (SIS), commonly known as MI6 (Military Intelligence, Section 6), is the foreign intelligence service of the United Kingdom, tasked mainly with the covert overseas collection and analysis of human intelligence on foreign nationals in support of its Five Eyes partners. SIS is one of the British intelligence agencies and the chief of the Secret Intelligence Service (known as "C") is directly accountable to the foreign secretary.

Formed in 1909 as the Foreign Section of the Secret Service Bureau, the section grew greatly during the First World War, officially adopting its current name around 1920. The name "MI6" originated as a convenient label during the Second World War, when SIS was known by many names. It is still commonly used today. The existence of SIS was not officially acknowledged until 1994. That year the Intelligence Services Act 1994 (ISA) was introduced to Parliament, to place the organisation on a statutory footing for the first time. It provides the legal basis for its operations. Today, SIS is subject to public oversight by the Investigatory Powers Tribunal and the Intelligence and Security Committee of Parliament.