Our History



Although there’s evidence of British intelligence organisations collecting foreign intelligence and intercepting messages as far back as the 15th Century, our modern history really begins in 1909. With the growth of Germany’s naval and military strength and its expanding colonisation, particularly in Africa and the Pacific, the British government was increasingly concerned about the threat to its Empire. In the early 1900s scare stories in the UK press about German espionage were common and even the Director of Military Operations was convinced that Germany was targeting Britain. These rumours were overblown, but in reaction to popular concerns, Prime Minister Herbert Asquith ordered the Committee of Imperial Defence to look into the matter. In July 1909 they established a Secret Service Bureau, split into Home and Foreign Sections.


Mansfield Cumming

The Original 'C'

Mansfield Cumming, a 50-year-old Royal Navy officer, was chosen to lead the Foreign Section of the Secret Service Bureau, which was our first official name.

Cumming was an unusual choice – he had no intelligence experience or linguistic skills. But he was recommended for the role due to ‘special qualifications’. He was, however, a workaholic and started work in October 1909, a week early. So it’s no surprise that his diary entry for that first day read: 'went to the office and remained all day, but saw no one, nor was there anything to do there.'


Ashley Mansions

At first the Foreign and Home Sections shared an office. But Mansfield Cumming soon decided that we needed our own base – somewhere that included accommodation. He chose Ashley Mansions in Vauxhall Bridge Road and early in 1910, he set up a bogus address with the Post Office – Messrs Rasen, Falcon Limited, a firm of ‘shippers and exporters’. This was the first example of the classic ‘import/export’ espionage cover. Anything sent to this address was forwarded to Cumming at Ashley Mansions.

Whitehall Court

In 1911 we were on the move again – this time to 2 Whitehall Court, next to the War Office and close to the Admiralty and Foreign Office. Our numbers were growing and this gave us more space. During the First World War, our role and workforce both continued to grow, which led to further expansion into other offices. We interviewed and assessed potential officers at a building in Kingsway, while a ‘very secret’ Air Section was based in South Lambeth Road.


Outbreak of


Just two months after the start of the war, in October 1914, Cumming was involved in serious car accident in France that killed his son. Cumming suffered two broken legs and had to have his left foot amputated, which resulted in a stay of a few months in hospital. This meant he had to delegate some work he’d previously done himself. It also led to closer ties with the War Office and the development of its own independent service by the military.

The long-term result of this accident was that, in 1916, we became part of the War Office, known as MI1(c). Cumming retained autonomy and still reported to the Foreign Office, but he faced a lot of opposition from the military, who thought our operations should be merged with theirs, under their control.

The war was a period of dramatic growth and change for us and our work had a major influence on the eventual victory.

Intelligence from


In November 1914 Cumming’s Rotterdam station was approached by Karl Krüger, a former German naval officer, who offered his services as an agent – at a price. He had access to a number of German shipyards and toured them once a month from May 1915 until January 1919. This enabled him to gather a wide range of information on naval construction and fleet movements, as well as vital intelligence on German losses, such as those at the Battle of Jutland in 1916. He was recruited, given the code name TR/16 and continued to provide crucial data throughout the war.


'La Dame Blanche'

'La Dame Blanche' was a network of spies in German-occupied Belgium that supplied valuable information on German troop movements. Its two leaders, Walthère Dewé and Herman Chauvin agreed for the group to work as our agents in 1917. By that stage the operation was already recording German troop movements and by the end of the war it had almost 800 members – many of them women – and 80 train watching stations.

By watching German trains going through Belgium day and night, they passed important data to British intelligence in the Netherlands. Messages were passed on using a variety of methods – in one case, a midwife, whose job allowed her to cross military lines, regularly carried reports wrapped around the whale bones of her corset. By the end of the war, intelligence from ‘La Dame Blanche’ was informing the British of enemy activities on an almost daily basis.


Recruiting a

diverse workforce

Throughout the war our organisation relied heavily on women, who worked as secretaries, typists, clerks and drivers. In fact, Cumming took the unusual step for the period of recruiting both married and unmarried women – in other areas of the Civil Service at the time, women had to resign after they married. He also paid his female staff higher salaries than those paid to women in other government departments.

Cumming was also keen to recruit military officers who’d been wounded and were no longer fit for service at the front.


Sir Paul Dukes

In Russia

At the end of the war, we focused on the rise of the Bolsheviks in Russia and the establishment of a communist state. One undercover officer was Paul Dukes, who went into Russia in late 1918, posing first as a post office clerk, then an epileptic and eventually, ‘Comrade Alexander Bankau’, a soldier in the Automobile Section of the VIIIth Army. He reported on living conditions, and when he based himself in Petrograd (modern-day St Petersburg) he monitored the movements of the Baltic Fleet.




The war years had seen our operations expand, but immediately afterwards there was constant pressure to reduce costs. This resulted in another office move, away from Whitehall to smaller premises in Melbury Road, Holland Park.

Cumming’s concerns about secrecy were so strong that some visitors had to go to another office off the Strand, where they were given the Holland Park address. He even considered not revealing the address to the Director of Military Intelligence.


What's in a


From 1909 and through the war we’d had a variety of names, including the 'Foreign Intelligence Service', the 'Secret Service', 'MI1(c)', the 'Special Intelligence Service' and even 'C's organisation'. But, around 1920, the title the Secret Intelligence Service (SIS) was adopted. This is the official title we’ve continued to use ever since.



The 'Father of SIS'

Mansfield Cumming left a legacy that still exists here today. He called intelligence reports ‘CX reports’ – the name we still give them. He established SIS as a truly worldwide service. He always wrote his letters in green ink – a practice that the Chief continues to this day. And, perhaps most notably, he was known as ‘C’, the name given to every Chief since.


A New Chief

After Mansfield Cumming died in 1923, his successor was Rear Admiral Hugh Sinclair. He was a former Director of Naval Intelligence, in contrast to Cumming, who’d been a relatively junior officer when he was appointed in 1909. Importantly, as well as becoming Chief of SIS, Sinclair also became responsible for the Government Code & Cypher School (GCCS) – the forerunner to GCHQ.


A More Permeanent


In our first 17 years, we’d been based in four different buildings around London while various senior figures had tried to establish our role. In 1926 we moved into Broadway Buildings, 54, Broadway, near to St James's Park underground station, with GC&CS. When war broke out in 1939, GC&CS moved out to its new base at Bletchley Park, while we stayed in Broadway. It was our home until 1964.


The Jonny Case

In 1933 Johann (‘Jonny’) de Graff, a German communist and Comintern agent, contacted Frank Foley, the head of the SIS Berlin station. Following his recruitment De Graff supplied valuable information on Communist attempts to infiltrate the British armed forces. He also provided intelligence on Comintern activities in China and Brazil, including technical details of Comintern aliases, plans and even descriptions of agents.

In Brazil, Jonny managed to disrupt a planned Communist revolution that would have jeopardised a large number of British companies in the country. He was sent by the Comintern to support the revolution and in November 1935, he passed on information that leftist Brazilian army units were planning to mutiny. This tip-off resulted in a power cut in the relevant barracks, engineered by the local power company, which meant the mutineers couldn’t use their radios and the rising was put down.


Preparing for war

Section D
'For Destruction'

As the threat of Nazi Germany increased in the late 1930s, we began to prepare for the possibility of war. As part of this, in 1938, we set up Section D under Laurence Grand. Section D’s aim was simple – ‘to plan, prepare and when necessary carry out sabotage and other clandestine operations, as opposed to the gathering of intelligence.’

Grand set out plans for targeting Germany’s electricity industry, phone communications, railways, food supplies and agriculture. He also wrote a report on how to defend Britain against sabotage – including protecting power stations and communications, guarding London underground against bacteriological attack and defending milk deliveries to senior public figures against tampering.

In 1940, Section D became part of the Special Operations Executive (SOE), which carried out a large number of sabotage operations across Europe during the war.



Bletchley Park

In July 1938, Hugh Sinclair bought Bletchley Park in Buckinghamshire for £6,000 as a wartime base for SIS and GC&CS. During the Munich Crisis in September 1938, Head Office and GC&CS staff were transferred to Bletchley, although most of them returned to London soon afterwards. In early 1939 a 24-hour SIS communication service with four transmitters and six receivers was set up there. Members of Section D also moved to Bletchley in early 1939 to develop sabotage material, including incendiaries and plastic explosives.

In August 1939, as war became almost inevitable, the code breakers of GC&CS moved to Bletchley Park permanently.


A New Chief

Hugh Sinclair died in November 1939 and was replaced by his deputy Colonel Stewart Menzies, who took over a service that included 42 officers and 55 secretaries.

Menzies was Chief during the dramatic expansion of both SIS and GC&CS in the fight to win the war. By the beginning of 1944, 837 people worked at our headquarters. He regularly kept Prime Minister Winston Churchill informed of operations and the intelligence being gathered. In this way, he played an important role in the ‘secret war’, keeping his position when many around him lost theirs.


Wartime networks

‘Service Clarence’ was one of the most successful SIS network in Belgium during the war, led by Hector Demarque and Walthère Dewé, who had earlier played a leading role in ‘La Dame Blanche’. Throughout the war ‘Service Clarence’ provided valuable information on a wide range of enemy activity including coastal defences, the effects of Allied bombing and the location of German units.

The ‘Alliance’ Network in Occupied France was led by Marie-Madeleine Fourcade – described after the war by an SIS officer as the “copybook beautiful spy”. The network was extensive – by August 1942, a breakdown of members listed 145 agents. It was a source of high quality and detailed intelligence on enemy troop movements, German order of battle, and Nazi secret weapons.

Makir’ wireless station in Occupied Norway sent many messages to London reporting on the German occupying forces. It was run by Oluf Reed Olsen, who was parachuted into Norway in 1944 and set up the station near the entrance to Kristiansand Fjord. He reported on U-boat activity and German order of battle. His camp had to be well camouflaged to avoid detection and silence was vital – they even had to wake one man up to ten times a night because of snoring. But their vigilance paid off and they transmitted up to ten messages a day for over six months, without detection.


Professional training

Before the war, training for officers and agents had, to say the least, been haphazard. But as we continued to grow at a rapid rate, it became obvious that we needed a more systematic approach. So, in 1943, Commander Kenneth Cohen was appointed Chief Staff Officer, Training.

Three officers attended the first training course in the summer of 1943 and there were ten at the next, in September. By this stage, the Training Section was already producing instruction books and manuals for overseas stations. By the end of the year, there were different programmes available that officers could attend to brush up on, for example, their Tradecraft. By 1944, the Chief was already impressed with the benefits that better training were bringing to the Service and our staff.



The ‘Sussex’ scheme

In preparation for the Allied invasion of France in June 1944, we worked closely with our American and Free French allies to create special teams of agents. Codenamed ‘Sussex’ these men and women, working in pairs were trained to operate behind enemy lines and provide front-line intelligence after D-Day. By August 1944, just two months after D-Day, over 30 teams had been parachuted into France and they’d transmitted over 800 messages.


The Cold War

Even as the Second World War was drawing to a close, we were preparing to meet new challenges. With the emergence of the ‘Cold War’ between Western powers and the Soviet Union with its communist allies, we needed to be ready to meet different intelligence challenges.

The end of the war also resulted in some internal changes, with SOE becoming part of SIS.


Closer ties

with America

In 1948 we held the London Conference on War Planning, which was attended by senior officials from the newly created US Central Intelligence Agency (CIA). This series of meetings covered a range of practical issues in the event of war with Russia, such as joint handling of tactical intelligence, stay-behind projects, special operations planning and common training. The conference led to long-term liaison and a further meeting in 1949 in Washington cemented our close relations.

What next

In the early part of the 21st century, Sir John Scarlett, then Chief of SIS, commissioned a detailed and authoritative history of our organisation. The book, written by Professor Keith Jeffery of Queen’s University, Belfast, covered the period up to 1949 and all the historical events detailed on this page up to this point have been based on episodes in his book. 

So, what of the Service’s history since 1949? The truth is, secrecy’s at the heart of everything we do. After all, we’re not known as the ‘Not Quite’ Secret Intelligence Service. We’re the Secret Intelligence Service and releasing secrets could have significant consequences for both current and past SIS agents and officers.

This means, while we can give a few details of what’s happened since 1949, the only way for you to find out more is to join us.


Dick White

Joins from MI5

Dick White’s the only person to have headed both SIS and MI5. He was Director General of MI5 from 1953-56 when Prime Minister Eden asked him to take over SIS, where he was Chief until 1968. 

In 1964, White oversaw our move from Broadway Buildings, which had been our headquarters for 38 years, to Century House, a tower block in Westminster Bridge Road, Lambeth. This was better suited to our needs in modern times and was our home for thirty years.

This means, while we can give a few details of what’s happened since 1949, the only way for you to find out more is to join us.


An Iconic


In 1994 we moved to our current headquarters, Vauxhall Cross – the building you probably know from its appearances in several James Bond films.

The architect Terry Farrell won the competition to develop a building on the site and took his inspiration from 1930s architecture such as Battersea and Bankside power stations, as well as Mayan and Aztec temples. With 60 different roof areas and six perimeter and internal atria, it incorporates specially designed doors and 25 different types of glass to meet our specific needs. It was officially opened by Her Majesty the Queen in July 1994 and has been home to SIS ever since.



Service Act

The Intelligence Services Act, 1994, was the first public acknowledgement of the existence of both SIS and GCHQ. More importantly, it also defined our role and set out the legal parameters under which we operate. The Act also established the Intelligence and Security Committee in parliament to scrutinise all three intelligence services.

A 21st Century


The secret nature of our work means we can’t give much information on our operations since. So, many of our more recent successes have gone unnoticed.

What we can say, however, is that we’ve contributed to the disruption of numerous terrorist attacks overseas and in the UK. Working closely with MI5, GCHQ and the police, we helped to protect the London 2012 Olympics. Our work contributed to reaching an agreement with Libya to disband and destroy their WMD capability and the subsequent admission of inspectors to oversee this dismantling. UK intelligence also enabled the disruption of the AQ KHAN network, which was selling nuclear technologies to countries of concern. As new threats to UK security continue to emerge around the world, we’re playing a major role in safeguarding the country’s people and interests.