MI6 (Military Intelligence, Section 6), United Kingdom
Arguably the most famous of the world’s espionage agencies, MI6 is the United Kingdom’s (UK) storied foreign intelligence apparatus. As previously noted, gauging the success of an intelligence agency is difficult, but given that several organizations modeled themselves after the UK’s, it doesn’t take a spymaster to discern MI6’s elite status. Unlike other agencies, portions of MI6’s origin story remain the subject of scholarly debate. This is largely the result of the British Official Secrets Act, which empowered State security regarding intelligence, but has the nasty side effect of locking information away and then forgetting about it. UK security aside, most of MI6’s origin story is publicly available.
Similar to other nations, the UK used various intelligence units throughout its history, but a permanent agency didn’t evolve until 1909 when the War Office created the Secret Service Bureau, the brainchild of a former police detective, William Melville. Melville joined the Metropolitan Police (Scotland Yard) in 1872, and, over the course of a thirty-one-year career, rose to prominence and fame through a series of highly publicized investigations and plot foiling’s (at least one of which Melville instigated). Key to the future of MI6, however, was Melville’s role as Superintendent of Scotland Yard’s Special Branch, which performed numerous intelligence operations typically handled by agencies at the national level. Thus, Melville’s retirement announcement in 1903 surprised both the British public and press. Melville was only fifty years old; an extremely successful, powerful, man at the peak of his career. The move simply didn’t make sense.
Behind the scenes, however, the beginning of the UK’s intelligence agencies was unfolding. Secretly recruited by the government, Melville headed a new intelligence unit for the War Office, MO3, later redesignated MO5. He ran both intelligence and counter-intelligence from a non-descript flat in London, and quietly lobbied the government to establish a permanent agency. In October 1909, the government established the Secret Service Bureau, comprised of nineteen departments, MI1 through MI19.
This is where the scholars get argumentative. Melville retired in 1917, and died in 1918, but whether he was the head of the entire organization, who used the code name “M,” or the agency’s chief detective with his own section remains a matter of debate.