Mansfield Smith, the youngest in the family of five sons and eight daughters of Colonel John Thomas Smith of the Royal Engineers, and his wife, Maria Sarah Tyser, was born on 1st April 1859. He came from a moderately prosperous landed and professional family. After attending Dartmouth Royal Naval College, he served as sub-lieutenant in HMS Bellerophon. Smith saw action in the East Indies and was decorated for his role in the Egyptian campaign of 1882.
Smith suffered from poor health and in 1885 was placed on the retired list as "unfit for service". He married the extremely rich May Cumming and as part of the marriage settlement changed his name to Smith-Cumming. In 1898, while still on the Royal Navy retired list, he was recruited by the foreign section of the Secret Service Bureau. This organization had responsibility for supplying intelligence to the Admiralty and to the War Office.
In 1907 Major Vernon Kell become Director of the Home Section of the Secret Service Bureau with responsibility of investigating espionage, sabotage and subversion within and without Britain. In 1909, a new section, headed by Cumming became responsible for for secret operations outside Britain. This organisation eventually became known as MI6. Keith Jeffery, the author of MI6: The History of the Secret Intelligence Service (2010), argues: "Cumming was an inspired choice. Not only did he grasp the essentials of secret service work from the very beginning, but he proved to be sufficiently robust and independent-minded to ensure the continued autonomy of the fledgling service."
Vernon Kell was appointed as head of MI5, investigating espionage, sabotage and subversion in Britain. Cumming feared that Kell would eventually become head of a unified intelligence unit. On 1st November 1909 he wrote: "I am firmly convinced that Kell will oust me altogether before long. He will have quantities of work to show, while I shall have nothing. It will transpire that I am not a linguist, and he will then be given the whole job with a subordinate, while I am retired - more or less discredited."
The historian, Christopher Andrew, has pointed out: "Between 1909 and 1914 he recruited part-time casual agents in the shipping and arms business to keep track of naval construction in German shipyards and acquire other technical intelligence. He also had agents collecting German intelligence in Brussels, Rotterdam, and St Petersburg."
Cumming worked long hours. He wrote in his diary in August 1910 that he worked from "9.30 am to 11.30 pm, with 2 hours off, say 12 hours (a day), but I get very short Saturday afternoon and no Sunday. It is bound to continue for a year or two, but after that should settle down." Initially, Cumming's main task was to collect evidence of German planning for a war against Britain. Without the resources to employ full-time agents, Cumming was unable to find any evidence of such a plan. His most important agent was Sidney Reilly based in St Petersburg.
According to Christopher Andrew, Cumming had a reputation for driving his Rolls Royce "at high speed around the streets of London... Their only son, Alastair, a dangerous driver like his father, was killed in October 1914, driving Cumming's Rolls in France. Cumming himself lost the lower part of his right leg in the same accident." Keith Jeffery points out "he was back to work at his office in London within about six weeks testifies to very considerable powers of resilience and fortitude."
Working closely with Vernon Kell of MI5 and Sir Basil Thomson of the Special Branch, Smith-Cumming helped to arrange on the outbreak of the First World War the arrest of 22 German agents. Eleven men were executed, as was Sir Roger Casement, who was also found guilty of treason. The government was so pleased with the work of Cumming that on 17th November 1915, he was given the title "Chief of the Secret Service" and was given "sole control" of "all espionage and counter-espionage agents abroad" and of "all matters connected with the expenditure of Secret Service funds".
During the war Cumming's unit became known as MI6. Agents who worked for the unit during the war included John Buchan, Valentine Williams, Edward Knoblock, Compton Mackenzie and Somerset Maugham. Knoblock later commented: "He (Cumming) did us all almost endless kindnesses, as not only the men but the girls who worked for him will remember to this day." Williams was also complimentary, claiming he "had nerves of steel... In the darkest moments, it was a tonic to his staff to see him at his desk, calm, affable, humorous, unafraid".
The author of MI6: The History of the Secret Intelligence Service (2010) has argued: "A large part of Cumming's success stemmed from his cheerful and equable personality. Whatever professional disagreements he may have had with fellow officers, he always seems to have been able to maintain good relationships on a personal level." Another agent, Paul Dukes, later recalled "woe betide the unfortunate individual who ever incurred his ire... but the stern countenance could melt into the kindliest of smiles, and the softened eyes and lips revealed a heart that was big and generous".
In July 1919 Cumming was awarded a KCMG, in the prestigious Order of St Michael and St George, normally reserved for ambassadors and colonial governors. This was a clear public recognition of the high esteem in which he was held and the service he provided during the First World War. Despite this acceptance of the important work of MI6 during the war, the government cut back on expenditure on the Secret Service and as a result Cumming lost stations in Madrid, Lisbon, Zurich and Luxembourg.
Christopher Andrew has pointed out: "Like the rest of the British intelligence community, the post-war SIS was drastically cut back. Cumming succeeded, however, in gaining a monopoly of espionage and counter-intelligence outside Britain and the empire. He also established a network of SIS station commanders operating overseas under diplomatic cover. To the end of his life Cumming retained an infectious, if sometimes eccentric, enthusiasm for the tradecraft and mystification of espionage, experimenting personally with disguises, mechanical gadgets, and secret inks in his own laboratory."
In 1919 the War Office suggested that MI6 should amalgamate with MI5. Cumming argued strongly against this proposal. As Keith Jeffery has pointed out: "He saw clearly... the absolute necessity of keeping domestic and foreign intelligence work separate. Anticipating the possibility of a Labour government, and managing to do so in an admirably unhysterical way, Cumming asserted that combining his organisation with M15 and getting involved in secret service against domestic political targets could jeopardise the effectiveness of foreign intelligence work by prompting public and parliamentary attacks on the intelligence machine as a whole.... Or he may simply have appreciated that the active espousal of anti-left-wing politics could damage the work of his beloved Bureau. Whatever the reason, his decision to distance the Bureau from domestic security and intelligence work was absolutely sound."
Sir Mansfield Smith-Cumming died suddenly at his home in Kensington on 14th June 1923, shortly before he was due to retire.
A further important factor working to Cumming's benefit was the restricted view he took of what the Secret Service Bureau should actually do. There is no suggestion in the surviving documentation that he ever saw the function of his organisation as being more than the collection and distribution of information, as requested by other government departments. At no stage did he seek to offer policy advice, or even very much to analyse or manipulate the information gathered by his officers and agents. For him, the Bureau was simply an expert organisation, designed to respond as best it could to the requirements of customer departments. And, unlike some others in the intelligence world - Colonel French during the war, Basil Thomson immediately after, and even Cumming's successor, Hugh Sinclair, in the inter war years - he never showed any tendency towards empire-building. When the Bureau grew, it did so organically and in response to customer demand. Cumming's institutional ambition was not in the slightest acquisitive (which could have made him enemies), but consistently protective, vigorously defending his organisation from the threatened depredations of other departments. His obsession, moreover, with secrecy (the "first, last and most necessary essential") had a beneficial and self-effacing effect. By consistently maintaining as low a profile as possible, neither he nor his organisation appeared to threaten anyone else.
A final, and extremely significant, feature of Cumming's time as Chief is the shrewd political judgment he demonstrated in the face of the 1919 War Office proposal to amalgamate his department and MI5, at a time when ministers and officials alike were gripped by fears that Red Revolution might engulf the United Kingdom. Everything in Cumming's class and career background would have disposed him towards diehard right-wing political attitudes, militantly opposed to the threat of the Labour movement and socialism (let alone that of Communism). But what is remarkable about Cumming, in contrast to other toilers in the intelligence vineyard, such as Blinker Hall (a Conservative MP from 1918 to 1923), Thomson and Sinclair (certainly when he was Director of Naval Intelligence), who were prepared at times to let their right-wing political views supersede the obligations of constitutional government, is that, whatever his private political opinions, he carefully and wisely distanced himself and his organisation from domestic British politics. He saw clearly, as his successor Stewart Menzies was also to do twenty-five years later, the absolute necessity of keeping domestic and foreign intelligence work separate. Anticipating the possibility of a Labour government, and managing to do so in an admirably unhysterical way, Cumming asserted that combining his organisation with M15 and getting involved in secret service against domestic political targets could jeopardise the effectiveness of foreign intelligence work by prompting public and parliamentary attacks on the intelligence machine as a whole. As with his passion for motor cars, speedboats and aeroplanes, Cumming, a nineteenth-century Victorian with a lively twentieth-century interest in technological advances, may have been more prepared to accept political change than many of his contemporaries. Or he may simply have appreciated that the active espousal of anti-left-wing politics could damage the work of his beloved Bureau. Whatever the reason, his decision to distance the Bureau from domestic security and intelligence work was absolutely sound.
Cannot do any work in office. Been here five weeks, not yet signed my name. Absolutely cut off from everyone while there, as cannot give my address or be telephoned to under my own name. Have been consistently left out of it since I started. Kell has done more in one day than I have in the whole time...
The system has been organised by the Military, who have just had control of our destinies long enough to take away all the work I could do, hand over by far the most difficult part of the work (for which their own man is obviously better suited) and take away all the facilities for doing it.
I am firmly convinced that Kell will oust me altogether before long. He will have quantities of work to show, while I shall have nothing. It will transpire that I am not a linguist, and he will then be given the whole job with a subordinate, while I am retired - more or less discredited.
Called on Kell at his request handed over my small safe and the keys to my desk to his Clerk... He asked me if I should object to his coming next door, but t told him that I thought it would interfere with my privacy in my own flat and I begged he would not go forward with any such scheme. I would rather he were not in this immediate neighbourhood at all.
Cumming's most remarkable, though not his most reliable, agent was Sidney Reilly in St Petersburg, the dominating figure in the mythology of modern British espionage. Reilly, it has been claimed, "wielded more power, authority and influence than any other spy", was an expert assassin "by poisoning, stabbing, shooting and throttling", and possessed "eleven passports and a wife to go with each". The reality, though far less sensational, is still remarkable. Reilly was born Sigmund Georgievich Rosenblum in 1874, the only son of a rich Jewish landowner and contractor in Russian Poland. Some time in the 1890s he left home, broke off all contact with his family, and emigrated to London. At the turn of the century, having changed his name to Reilly, he moved to Port Arthur, the base of the Russian Far Eastern Fleet, where he worked first as partner in a firm of timber merchants, then as manager of the Danish Compagnie Est-Asiatique. By the time Reilly returned to London on the eve of the Russo-Japanese War in 1904, he had become a self-confident international adventurer, fluent in several languages, already weaving around his cosmopolitan career a web of fantasy which has since ensnared most of those who write about him. "He had", writes his most recent biographer, "passed his test with the SIS with flying colours, and they decided that they had a most promising recruit on their hands, who merited very special training". Not the least problem with this romantic view of Reilly's intelligence initiation is that SIS did not yet exist. It is quite possible, though there is no proof, that Reilly did provide NID with intelligence on the Russian Far Eastern Fleet during his years in Port Arthur. But it is scarcely possible that his unusual experience of higher education over the next few years was specially devised as a training programme by NID. In 1904-5 he successfully completed a year's course in electrical engineering in the Royal School of Mines. In October 1905 he went up to Trinity College, Cambridge, as an "advanced student" but left two or three years later without taking any degree.