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.

There was a darker side to Reilly's personality, one that was to haunt Mansfield Cumming for many years. He was a compulsive gambler and a reckless one to boot. He spent his money with great ostentation, staking all on a hand of cards.

What struck everyone was Reilly's vaunting ambition. He detested the Bolsheviks and was already dreaming of toppling Lenin's government. When he had come to consider who might replace Lenin, he looked no further than the mirror.

"Behind all Reilly's efforts lay the conviction that some day he was destined to bring Russia out of the slough and chaos of Communism," wrote Norman Thwaites. "He believed that he would do for Russia what Napoleon did for France."

Reilly had long identified himself with Napoleon. It was an alarming comparison in one who was preoccupied with turning fantasy into reality. Such was his fascination with his historical hero that he amassed a large collection of memorabilia - a collection he would eventually sell for the considerable sum of $100,000.

Cumming had been fully briefed on Reilly's dubious background when he called him in for a meeting on 15 March 1918. His interviews with potential agents were usually cordial but perfunctory and there is no reason to doubt that his meeting with Reilly was any different. He must surely have asked him about his contacts in Russia and his political affiliations, but the content of their conversation remains unknown for Cumming recorded only a brief mention of their encounter in his diary. He found Reilly charming, yet he clearly had concerns. "Very clever," he wrote, "very doubtful - has been everywhere and done everything."

His resourcefulness was an important point in his favour: Reilly was exceptionally good at adapting himself to unfamiliar surroundings. Hector Bywater said that "the good intelligence man had to dig himself in and stick it, bearing loneliness and fear and excitement and triumph in complete silence."

Reilly fitted this mould so exactly that Cumming was prepared to turn a blind eye to Reilly's defects and send him into Russia, although he confessed that employing him was "a great gamble".

"He will take out £500 in notes and £750 in diamonds, which are at a premium," wrote Cumming in his diary.
The British government were playing with high stakes: Reilly was being given the modern equivalent of £50,000.

Ten days after his meeting with Mansfield Cumming, Reilly - now bearing the codename STl (the ST stood for the Stockholm bureau) - was en route to Bolshevik Russia. The plan was for him to enter the country at the port of Archangel and then make his way overland to Moscow, the new capital.

Cumming contacted his operatives in Vologda, 300 miles to the south of Archangel, and informed them of the imminent arrival of Reilly. "A Jewish-Jap type," was how he described him, "brown eyes very protruding, deeply lined sallow face, may be bearded, height five foot nine inches.".

Cumming added that he "carries code message of identification ... ask him what his business is and he will answer: "Diamond Buying." This bogus occupation was rendered more believable by the fact that he was carrying sixteen large diamonds.

Reilly was not travelling incognito on the first stage of his journey. Shortly before leaving London, he had been issued with an official business visa by Maxim Litvinoff, the Bolshevik government's sole representative in London. He was one of a small group of emigres who had remained in England after the two Russian revolutions of 1917. Now, he found himself playing a role similar to that of Robert Bruce Lockhart.

Litvinoff was wholly ignorant of the fact that Reilly was being sent to Russia as a spy. Nor did he know that Reilly detested Lenin's new regime. He took Reilly at face value and believed his claim to be a bona fide businessman who was keen to serve the new Bolshevik government.

Reilly's independent spirit got the better of him before he even arrived at his destination. Instead of disembarking at Archangel, as Cumming had requested, he left the ship at Murmansk. He may have done this because he knew there was a direct train to Petrograd, but it meant that he immediately drew attention to himself. The port was being guarded by a small team of British marines who had been sent to prevent the stockpile of Allied munitions from falling into German hands. These marines promptly arrested Reilly and locked him up in HMS Glory until they had completed their investigations.

It was fortunate that another of Cumming's operatives, Stephen Alley, happened to be in Murmansk at the time. The soldiers summoned Alley on board and asked for his opinion of this strange new arrival. "His passport was very doubtful and his name was spelt REILLI," wrote Alley. "This, together with the fact that he was obviously not an Irishman, caused his arrest."

But Reilly was able to provide proof of his status. He uncorked a bottle of medicine and produced a minuscule message written in code. Alley immediately recognised it as a code of the Secret Intelligence Service and Reilly was released. He was free to continue his onward journey.

Alley himself was travelling in the other direction, returning to London under something of a cloud. He had been fired by Cumming for reasons that remain obscure: Alley would later make the sensational claim that he had been sacked for failing to carry out an order to assassinate Joseph Stalin, already a member of Lenin's inner circle.

"I didn't always obey orders," he admitted. "Once I was asked to rub out Stalin. Never did like the chap much ... [but] the idea of walking into his office and killing him offended me."

Reilly was supposed to head directly to Moscow. Instead, he took the train to Petrograd in order to make contact with a number of old friends who might prove of use to him. He had not visited the city since 1915 and found that much had changed. War and revolution had left deep scars on the population and an air of decay hung like a stinking pall over the city's imperial boulevards.

"The streets were dirty, reeking, squalid. Houses here and there lay in ruins. No attempt was made to clean the streets, which were strewn with litter and garbage."

When Reilly had visited three years previously, queues for bread had been a fact of daily life. "Now... the bread queues were still there, but there was no food at all."

More alarming was the presence of the newly founded Cheka, whose officers seemed to lurk on every street corner.

"There was no police except for the secret police," wrote Reilly, "which held the country in thrall." It was testimony to Dzerzhinsky's efficiency as head of the Cheka that it was already a malign presence in everyone's lives, despite having been established just three months earlier.

Reilly took care not to draw attention to himself, for the last thing he wanted was to make his presence known to Lenin's secret police. He made his way to the house of an old friend, Yelena Boyuzhovskaya, hoping that he was not yet being tracked. He confessed to being in a`cold bath of perspiration' when he finally reached her apartment.

"Watching that I was not observed, I slipped into the house. It might have been a necropolis I entered, and my footfall awoke a thousand echoes". He was delighted to find Yelena at home; she gave him a friendly welcome.

Reilly had equipped himself for many different eventualities during his time in Russia. He had entered the country on a genuine passport and intended to remain as Sidney Reilly for as long as was possible. But he was also prepared to change his identity and live in disguise if and when that became necessary.

He began perfecting several different personas while staying at Yelena's apartment. He was to have two principal identities, one for Moscow and one for Petrograd. In Petrograd, he would pose as a Levantine merchant named Konstantine Markovich Massino. The Massino name was adopted from his second wife, Nadine: it perfectly suited the polyglot merchant he was pretending to be.

He was so proud of this Massino disguise that he had himself photographed for posterity. With his luxuriant beard and oil-slicked hair he looked the picture of a prosperous Levantine entrepreneur.

At the age of nineteen he discovered that he was not his father's son at all, but the product of an illicit union between his mother and a Jewish doctor from Vienna. It is not surprising, therefore, that Reilly told different stories about his origins, even to people who thought they knew him well. Many years later, when having his passport endorsed while working for the British, he was asked, "How comes it, Mr Reilly, that you yourself admitted several times you were born in Odessa?" "There was a war and I came over to fight for England," replied Reilly. "I had to have a British passport and therefore a British birthplace, and you see, from Odessa, it's a long, long way to Tipperary!"

After discovering his true identity Reilly left his family and stowed away on a British ship bound for South America. There followed a variety of jobs as docker, road-mender and plantation worker, but finally he became cook to a British expeditionary party in Brazil, led by Major Fothergill of the British Secret Service. From about 1896 onwards, he was firmly involved in international espionage. At first he was no more than a freelance agent for the British, but shortly before the Russo-Japanese War he turned up in the Far East as a double-agent serving both the British and the Japanese. Suddenly he went off to China and lived in a lamasery for several months, allegedly becoming a Buddhist. Then he returned to Russia and, while still working for the British, is alleged to have started spying for the Tsarist regime. He was certainly being well paid as in 1906 he had a lavish apartment in St Petersburg, a splendid art collection and was a member of the most exclusive club in the city. At this time, of course, Britain and Russia were allies so that this did not mean that he was double-crossing the British. But he had almost certainly double-crossed the Japanese to whom he had previously sold information about Russia.

Reilly frequently acted on his own initiative. For example, when working as a welder in Krupp's arms factory in Germany before World War I, he not only stole plans of the factory, but killed two watchmen in making his getaway. Then he got the job as sole agent in Russia for a firm of German naval ship-builders. By this means he managed to see and copy all blueprints and specifications of the latest German naval construction. These he passed back to Britain.

I told "C" (and I am anxious that you should know it too) that I consider that there is a very earnest obligation upon me to continue to serve - if my services can be made use of in the question of Russia and Bolshevism. I feel that I have no right to go back to the making of dollars until I have discharged my obligations. I also venture to think that the state should not lose my services. I would devote the rest of my wicked life to this kind of work. "C" promised to see the F.O. about all this.

I need not enlarge upon my motives to you; I am sure you will understand them and if you can do something I should feel grateful. I should like nothing better than to serve under you.

I don't believe that the Russians can do anything against the Bolsheviks without our most active support. The salvation of Russia has become a most sacred duty which we owe to the untold thousands of Russian men and women who have sacrificed their lives because they trusted in the promise of our support.

Boris Savinkov introduced Spears to the spy Sidney Reilly. Born Rosenblum of Jewish ancestry in Odessa, Reilly had worked as a businessman in St Petersburg. After the revolution, he showed courage on behalf of his British paymasters even if some of his ideas were impractical; one of these was to debag Lenin and Trotsky and parade the humiliated pair through the streets. Reilly worshipped Napoleon and was both intensely secretive and wildly boastful. He had been with Denikin's forces in south Russia and, when Spears first met him, supported Savinkov, Spears became cautious about believing a man who claimed to have been attached to the German staff during the war...

Sidney Reilly was a difficult associate. Spears now had an office in London which the spy used when he was there; in October the telephone was cut off because Reilly had not paid the bill, there were exorbitant claims for expenses and the spy was rude when these were challenged. "I won't stand cheek," Spears said. He warned Reilly of "the danger of dealing with shady people & mixing politics with business". Reilly had damaged his position in Prague by identifying himself with Savinkov, "who is now out of favour there". The disadvantage of the spy, he decided, was the company he kept: "he is not careful enough."

Reilly marched up to the Kremlin gates in full dress uniform and informed the sentries that he was the personal emissary of Prime Minister David Lloyd George. He demanded to see Lenin.

It must have been a convincing act, for he was immediately granted entry and taken to meet one of Lenin's senior aides. However, no sooner was he inside the building than the Bolshevik officials manning the gates immediately began investigating the identity of this uninvited emissary.

Reilly's presence in Moscow was as yet unknown to the skeleton staff of the British Embassy. Robert Bruce Lockhart was taken by surprise when, at six o'clock that evening, he received a telephone call from Lev Karakhan, the Deputy Commissar for Foreign Affairs.

The commissar had an extraordinary story to recount. "That afternoon," he told Lockhart, "a British officer had walked boldly up to the Kremlin gate and had demanded to see Lenin."

Karakhan provided Lockhart with a few more details before asking if the man was an impostor. Lockhart was as perplexed as the commissar and asked to know more. He was told that the man's name "was Relli".

This meant nothing to Lockhart. "I nearly blurted out that he must be a Russian masquerading as an Englishman, or else a madman."

But he knew that Mansfield Cumming was intending to send new agents into Russia and he chose to bite his tongue. "Bitter experience ... had taught me to be prepared for almost any surprise and, without betraying my amazement, I told Karachin (sic) that I would inquire into the matter."

There was only one man who could tell him more. Ernest Boyce was now working as Cumming's principal agent in Moscow and he was also the link man with the main Stockholm bureau. Lockhart was sure that he would know the identity of this mystery individual.

Boyce was nonplussed when Lockhart recounted the story of Reilly's visit to the Kremlin. He calmly replied that, "the man was a new agent, who had just come out from England."

Lockhart was furious that he had not been pre-warned and "blew up in a storm of indignation." He insisted that Reilly come to the embassy on the following day in order to explain himself.

Reilly agreed to meet with Lockhart but made no apologies for his actions. Indeed, he expressed his surprise that Lockhart was so angry. "The sheer audacity of the man took my breath away... "fumed Lockhart, "although he was years older than me, I dressed him down like a schoolmaster and threatened to have him sent home."

Reilly, who was forty-five years of age, was amused to be ticked off by a man fourteen years his junior. He had already warmed to Lockhart and now used his natural charm to placate him. "He took his wigging humbly but calmly and was so ingenious in his excuses that in the end he made me laugh."

Lockhart was, by his own admission, captivated by the human chameleon seated opposite him. Reilly was the person he secretly wished to be. "The man who had thrust himself so dramatically into my life was Sidney Reilly, the mystery man of the British secret service," he would later write in his memoirs, "and known today to the outside world as the master spy of Britain." Reilly's methods, he said, "were on a grand scale which compelled my imagination."

Reilly returned to the Kremlin two days later, this time with his friend Grammatikov in tow. He was granted an audience with General Mikhail Bonch-Bruevich, Director of the Bolshevik's Supreme Military Council and "the brain centre of the entire Bolshevik organisation."

Reilly was at his loquacious best. He painted himself as a Bolshevik sympathiser, telling the general that he was "very interested in Bolshevism, the triumph of which had brought me back to Russia."

This was "quite true", noted Reilly in his memoirs; although he had obviously not come back to celebrate the triumph.
Reilly was anxious to discover two key pieces of information from the general. First, he wanted to know the state of relations between Germany and Russia now that the two countries were no longer at war. Secondly, he wanted to know if there were any divisions in the Bolshevik leadership.

He soon discovered that the leadership was split from top to bottom on the very issue of peace with Germany. The general himself was furious with the concessions that his fellow Bolsheviks had made to the German high command. Dropping his guard, he confessed to Reilly his fears that the Foreign Commissar, Georgy Chicherin, had been "bought by the Germans."

Reilly had been accorded a private glimpse into the rival factions that already existed in the new regime. One of his aims was to push Russia back to war. He now knew that this was not a forlorn hope: several senior Bolshevik commissars wanted to do the same.

Over the weeks to come, Reilly went out of his way to court the general. He quickly saw the benefit of cultivating contacts within the regime, commissars who could provide access to Lenin's inner circle.

"Nobody could be more officious on our behalf than Bruevich," wrote Reilly. He even supplied Reilly with a pass that enabled him to attend a meeting of the Soviets in the Grand Theatre.

Reilly sent a series of reports to Mansfield Cumming detailing the strengths and weaknesses of the Bolshevik leadership.

He admitted that their seizure of power was almost complete and that they were the "only real power in Russia". Yet he also revealed that the political opposition was growing in strength. "If properly supported," he wrote, "it will finally lead to the overthrow of the Bolsheviks."

Reilly proposed a twin-pronged strategy for dealing with Russia. The most immediate objective was to safeguard the stockpiles of Allied weaponry in the ports in Northern Russia. This would necessitate the landing of significant numbers of British troops, something that could only be done with the co-operation of the Bolsheviks.

At the same time, Reilly recommended funding the opposition movement with the long-term aim of toppling Lenin's government. "It may mean an expenditure of possibly one million pounds," he told Cumming, "and part of this may have to be expended without any real guarantee of ultimate success."

Reilly never received the one million pounds. It was far too much money for a country still at war. But his advice about safeguarding the Allied weaponry in the White Sea ports certainly struck a chord. There was a growing feeling in Whitehall that military intervention might be the only way of preventing the revolutionary government from playing fast and loose with the stockpile of munitions.

The stage was set for a dramatic power struggle, one which was witnessed by three key people: Arthur Ransome, Robert Bruce Lockhart and Sidney Reilly. All of them were present at a raucous political forum that took place at Moscow's Bolshoi Theatre on 4 July 1918.

The Fifth Congress of the Soviets was intended to provide a platform for political debate, but it presented Lenin with a serious problem. A third of the elected delegates were not Bolsheviks: rather, they were Lenin's political rivals - Socialist Revolutionaries - who stood in total opposition to peace with Germany. Now, they saw their chance to attack Lenin in public.

Robert Bruce Lockhart had been granted permission to attend the Congress as an observer. He arrived early at the theatre and was alarmed to notice that `every entrance, every corridor, is guarded by troops of Lettish [Latvian] soldiers, armed to the teeth with rifle, pistol and hand-grenade.' These troops were mercenaries, paid by the Bolsheviks to protect them from potential troublemakers.

The initial assault on Lenin was led by the leader of the Social Revolutionary party, Maria Spiridonova. With her neatly coiffed hair and pince-nez, she looked like a prim schoolmistress. But she was a schoolmistress with a ruthless streak. She denounced Lenin in a torrent of invective, accusing him of using the peasantry for his own political ends.
She then swung her gaze around to the peasant delegates in the theatre and harangued them for allowing themselves to be used as political pawns. "In Lenin's philosophy," she shouted in her high, shrill voice, "you are only dung - only manure."

Her speech provoked wild applause from the auditorium. "Pandemonium ensues," wrote Lockhart. "Brawny peasants stand up in their seats and shake their fists at the Bolsheviks. Trotsky pushes himself forward and tries to speak. He is howled down and his face blenches with impotent rage."

Arthur Ransome had joined Lockhart in the theatre and was equally impressed by the spectacle unfolding before him. He described Spiridonova as "looking like a nursery governess rapt into uncontrollable frenzy" and he listened enraptured as she "poured out a rhythmic, screaming denunciation of the Brest-Litovsk treaty."

Lenin sniffed at the danger: he faced the real risk of losing the support of the crowd. If so, the entire future of his revolution stood in jeopardy. Aware that only his oratory could pacify the rabble, he rose to his feet and delivered a highly skilful response that cast a spell over Spiridonova's supporters. Not for the first time, Ransome and Lockhart were witness to Lenin's hypnotic charm. Like a magician, he was able to transfix the crowd that had been baying for his blood just moments before.

"Gradually," wrote Lockhart, "the sheer personality of the man and the overwhelming superiority of his dialectics conquer his audience, who listen spell-bound until the speech ends in a wild outburst of cheering."

Lockhart knew that he was witness to an unequal political battle. He also knew that the final showdown between these political enemies was certain to have dramatic consequences.

Reilly is not a member of our office and does not serve C (Mansfield Cumming) in that he is not receiving any pay from us. He worked at one time during the war in Russia for C's organisation and is now undoubtedly of a certain use to us. We do not altogether know what to make of him. There is no doubt that Reilly is a political intriguer of no mean class, and therefore it is infinitely better for us to keep in with him, whereby he tells us a great deal of what he is doing, than to quarrel with him when we should hear nothing of his activities... he is at the moment Boris Savinkoff's right hand man. In fact, some people might almost say he is Boris Savinkoff. As such he has undoubted importance. In addition to the above, Reilly is of course a very clever man, indeed with means of finding out information all over the world. Whatever may be Reilly's faults, I personally would stake my reputation that he is not anti-British, at the moment at any rate, and never has been. He is an astute commercial man out for himself, and really genuinely hates the Bolsheviks. That is about all one can say of him.

Much as I am concerned about my own personal affairs which, as you know, are in a hellish state. I am, at any moment, if I see the right people and prospects of real action, prepared to chuck everything else and devote myself entirely to the Syndicate's interests. I was fifty-one yesterday and I want to do something worthwhile, while I can.

After prolonged deliberation, I express willingness to give you complete and open acknowledgement and information on matters of interest to the OGPU concerning the organization and personnel of the British Intelligence Service and, so far as I know it, similar information on American Intelligence and likewise about Russian emigres with whom I have had business.