He was a great-great grandson of the prominent merchant John Smith, a director of both the South Sea Company and the East India Company, the second son of Abel Smith, the Nottingham banker who founded a banking dynasty and whose business much later became National Westminster Bank, now one of the largest banks in the UK.
Early naval career
Smith joined the Royal Navy and underwent training at Dartmouth from the age of twelve and was appointed acting sub-lieutenant in 1878. He was posted to HMS Bellerophon in 1877, and for the next seven years served in operations against Malay pirates and in Egypt in 1883. However, he increasingly suffered from seasickness, and in 1885 was placed on the retired list as "unfit for service". Prior to being appointed to run the Secret Service Bureau, he was working on boom defences in Bursledon on the River Hamble. He added the surname Cumming after his marriage in 1889 to Leslie Marian Valiant-Cumming, heiress of Logie near Forres in the County of Moray.
Head of the SIS
Pre-1914
In 1909, Major Vernon Kell became director of the new Secret Intelligence Bureau and created as a response to growing public opinion that all Germans living in England were spies. In 1911, the various security organizations were re-organised under the SIB, Kell's division becoming the Home Section, and Cumming's becoming the new Foreign Section, responsible for all operations outside Britain. Over the next few years he became known as 'C', after his habit of sometimes signing himself with a C eventually written in green ink. That habit became a custom for later directors, although the C now stands for "Chief". Ian Fleming took these aspects for his "M" from the James Bond novels. In 1914, he was involved in a serious road accident in France in which his son was killed. Legend has it that to escape the car wreck he was forced to amputate his own leg using a pen knife. Hospital records have shown, however, that while both his legs were broken, his left foot was amputated only the day after the accident. Later he often told all sorts of fantastic stories as to how he lost his leg and would shock people by interrupting meetings in his office by suddenly stabbing his artificial leg with a knife, letter opener or fountain pen. Budgets were severely limited prior to World War I, and Cumming came to rely heavily on Sidney Reilly, a secret agent of dubious veracity based in Saint Petersburg.
World War I
At the outbreak of war he was able to work with Vernon Kell and Sir Basil Thomson of the Special Branch to arrest twenty-two German spies in England. Eleven were executed, as was Sir Roger Casement, found guilty of treason in 1916. During the war, the offices were renamed. The Home Section became MI5 or Security Service, while Cumming's Foreign Section became MI6 or the Secret Intelligence Service. Agents who worked for MI6 during the war included Augustus Agar, Paul Dukes, John Buchan, Compton Mackenzie and W. Somerset Maugham. When SSB discovered that semen made a good invisible ink, his agents adopted the motto "Every man his own stylo". However, the use of semen as invisible ink was ceased because of the smell it produced for the eventual receiver. It also raised questions over the masturbatory habits of the agents.
Anglo-Irish Insurgence
The Government Committee on Intelligence decided to slash Kell's budget and staff and to subordinate MI5 under a new Home Office Civil Intelligence Directorate led by Special Branch's Sir Basil Thomson in January 1919. The powerful partnership of MI5 and Special Branch had managed counterintelligence and subversives during the war, but that was suddenly thrown into disarray. These bureaucratic intrigues happened at the very moment when the Irish abstentionist party Sinn Féin and the Irish Republican Army were launching their own independence campaign. Cumming and SIS organized a new espionage unit in Ireland in mid-1920 called the Dublin District Special Branch. It consisted of some 20 line officers drawn from the regular army and trained by Cumming's department in London. Cumming also began importing some of his own veteran case officers into Ireland from Egypt, Palestine, and India, while Basil Thomson organized a special unit consisting of 60 Irish street agents managed by communications from Scotland Yard in London. On Sunday, 21 November 1920, the Headquarters Intelligence Staff of the IRA and its special Counterintelligence Branch under the leadership of Michael Collinsassassinated 14 of Cumming's case officers. Many agents appear to have escaped the IRA execution squads that morning, but Whitehall feared that more of its professional agents would be identified and suffer the same fate; this prompted the hasty withdrawal of most of the remaining SIS agents from Ireland in the days that followed. A blue plaque was unveiled on 30 March 2015 in Cumming's name at the SIS headquarters at 2 Whitehall Court.
Cumming was the basis for the fictional head of the SIS, named Control, in the John le Carréespionage novelThe Spy Who Came In from the Cold and other novels. In the movie version of le Carré's Tinker Tailor Soldier Spy Control signs his name as 'C' using green ink, as Cumming did in real life.
Cumming was also the basis for the fictional head of SIS in the original James Bond novels by Ian Fleming. Fleming chose to name his chief 'M' from Cumming's first name, Mansfield.