
The gateway to finding records at The National Archives is our catalogue, which you can access online.
You can search our catalogue for keywords of interest or browse it by key collections known as 'series'. This blog will introduce you to some of the series that relate to MI5 and intelligence work.

The starting point of our catalogue search.
Some of these records are only available in their original form. Our detailed Intelligence and security services research guide can help you search for those.
Many records of the British intelligence and security services have been digitised, however, and are available online. We'll introduce you to some of these in this blog.
Found something you're interested in? By clicking on a search result in our catalogue, you will find more details on how to view and download that record. Please note that charges may apply outside of The National Archives' building at Kew.
Individuals monitored by MI5
These personal files include records of suspected spies, renegades, communist sympathisers and right-wing extremists who were under surveillance at a point in their life. You can search them by name, codename, alias or names of known associates.
Series KV 2: Security Service Personal Files
Personal files from the First and Second World War periods and the interwar years.
Here is an example from the personal file of Walter Friedrich Schellenberg (KV 2/97), who rose to become one of the highest-ranking officials in the SS and Nazi Party’s intelligence agency. The file includes a translated copy of his autobiography, prepared for MI5, in which Schellenberg reflects on his motivations for joining the SS in 1933.

To: WRC3 (Mr. Ferguson)
Here at last is the translation of the Schellenberg opus. Whatever else he is, Schellenberg is a master of muddled and meaningless German. He also suffers badly from repetitive flatulence. To have allowed this to remain in the translation would have been to prove Schellenberg a language-criminal, but would not have been of much help to you, so the translators have done what they could to make it read as English, by no means an easy task.
W.R.D.
10.8.45.
Excerpt from the personal file of Walter Friedrich Schellenberg. Catalogue reference: KV 2/97
Special Operations Executive personnel files
These files contain the service records of Special Operations Executive (SOE) agents, who operated during the Second World War to carry out sabotage and subversion, and supported resistance movements in enemy-occupied territories.
Series HS 9: Special Operations Executive Personnel Files
Personnel files including medical reports, appraisals of performance and suitability for particular roles, as well as photographs and reports of the subjects' activities.
Additional SOE personnel files are available only in their original form. Due to the sensitive content of many documents, access may be restricted until 100 years after the individual’s birth.
HS 9/307/3 is the file of Marie Christine Chilver – also known as Agent Fifi or under her cover name, Christine Collard. She used subtle provocation to elicit information from unsuspecting recruits, testing their discretion and suitability for covert operations.

To Miss Collard.
17.4.43.
Will you please proceed to SHEFFIELD on Sunday 18th April to take part in an exercise? There is a train from St. Pancras at 12 o'clock arriving Sheffield at 4.33 p.m. Accommodation has been booked for you at Royal Victoria Station Hotel.
The R.S.L.O's telephone number is LEEDS 30785 (Major Hordern or Captain Marryst), but please do not make use of this except in an emergency.
The student whom you have to contact in this case is a woman, operating under the name of Mrs. Cicely HUMBLE. Her description is:
Age 35-40. Height 5'6. Slim build.
Shield-shaped face. Blue, wide-set eyes.
Straight nose. Thin lips - short upper lip.
Slim, long hands.
She will be in the Royal Victoria Station Hotel from 12.30 to 14.00 hrs. on Monday 19.4.43 - first in the cocktail bar, then lunch in the main dining-room, then coffee in the lounge.
Excerpt from the personnel file of Marie Christine Chilver. Catalogue reference: HS 9/307/3
Diaries of an MI5 intelligence officer
During the Second World War, Guy Liddell served as MI5’s Director of Counter-Espionage. From August 1939 to June 1945, he dictated a daily journal that offers a candid, behind-the-scenes account of MI5’s wartime operations.
Series KV 4, 185-196: Security Service Policy Files
Guy Liddell's work diaries from the Second World War.
His entries reveal concerns about threats from both the Soviet Union and the Nazi regime, detail the infiltration of enemy spy networks, and describe the handling of the 'Double Cross System.'
Although his friendships with Guy Burgess and Anthony Blunt led some to doubt Liddell’s probity, no evidence of his disloyalty was ever found. The diaries provide a unique insight and insider’s perspective on the workings of the Security Service during a pivotal period in history.
The history of the Security Service
We hold a number of documents chronicling the official history of the Security Service during the First World War, including a booklet written in 1959 by MI5 officer Gilbert Wakefield to commemorate the Service’s 50th anniversary.
Distributed to staff, the 34-page booklet condensed five decades of history, aiming to present the ‘facts rather than legends’ about the organisation.
Series KV 1: Security Service Historical Reports and Other Papers
The official history of the Security Service work during World War I compiled at the request of the Committee of Imperial Defence.

M.I.5.
(1909–1959)
The history of M.I.5 during its fifty years of existence can best be divided into three chapters.
In the first, from 1909 to 1914, it is seen as a very secret, very diminutive, almost private and personal entity, engaged solely in counter-espionage against the German Secret Service, and known (among the few to whom it was known) as "the Bureau."
In the second, from the outbreak of World War I in August 1914 till October 1931, it is "M.I.5"– a still secret (but not quite so secret) branch of the War Office military Intelligence department, increased in numbers, its functions widened by war-time legislation, still primarily concerned with counter-espionage, but after 1917, as a consequence of the Russian Revolution, with the added responsibility of combating Communist subversion in the armed forces.
And finally, since 1931, when for the first time in its history it became responsible for civil as well as military Security, the "Security Service" of today.
A page of Wakefield’s booklet, marked 'Secret', with a warning - staff were not permitted to remove it from the Office.
The Security Service policy files
These files record the Security Service's policies and ways of working on various subjects, mainly from the inter-war and Second World War periods. They include a catalogue, with photographs, of concealment devices used by German sabotage agents during the Second World War.
Series KV 4: Security Service Policy Files
Files setting out the Security Service's policies and procedures.

The bomb is made of steel with a thin covering of real chocolate. When the piece of chocolate at the end is broken off the canvas shown is pulled, and after a delay of seven seconds the bomb explodes.
Catalogue entry describing the mechanism of a German-engineered hand grenade disguised as a bar of chocolate. Catalogue reference: KV 4/284
Good luck with your research!
We hope these series and records provide a useful (and intriguing) starting point for your investigations. If you get stuck, you can contact us via our live chat service (Tuesday to Saturday 09:00 to 17:00) for advice and answers to specific questions about The National Archives' collections.