Editing MI5 (section)

===Early years===
The Security Service is derived from the '''Secret Service Bureau''', founded in 1909, and concentrating originally on the activities of the [[German Empire|Imperial German]] government, as a joint initiative of the [[British Admiralty|Admiralty]] and the [[War Office]].  The Bureau was initially split into naval and army sections which, over time, specialised respectively in foreign target [[espionage]] and internal [[counter-espionage]] activities. The former  specialisation was a result of a growing interest at the Admiralty, at the time, in intelligence regarding the fleet of the [[Imperial German Navy]].  This division was formalised, as separate home and foreign sections, prior to the beginning of the [[First World War]].  Following a number of administrative changes, the home section became known as [[Directorate of Military Intelligence (United Kingdom)|Directorate of Military Intelligence]], Section 5 and the abbreviation MI5, the name by which it is still known in popular culture.<ref>{{Cite web|url=http://www.SIS.gov.uk/output/Page470.html|title=SIS Records — War Office Military Intelligence (MI) Sections in the First World War|website=www.SIS.gov.uk|publisher=[[Secret Intelligence Service|SIS]]|url-status=dead|archive-url=https://web.archive.org/web/20060820014944/http://www.sis.gov.uk/output/Page470.html|archive-date=20 August 2006|access-date=21 November 2018}}</ref> (The foreign/naval section of the Secret Service Bureau was to become the basis of the later Secret Intelligence Service, or [[MI6]].)<ref>{{cite web |last= Whitehead|first=Jennifer|url=https://www.sis.gov.uk/our-mission.html|title=Our mission | publisher =SIS|date=15 July 2016 | access-date=25 August 2017}}</ref>

The founding head of the Army section was [[Vernon Kell]] of the [[South Staffordshire Regiment]], who remained in that role until the early part of the [[Second World War]].  Its role was originally quite restricted, as the section existed solely to ensure national security through counter-espionage.  With a small staff, and working in conjunction with the [[Special Branch (Metropolitan Police)|Special Branch]] of the [[Metropolitan Police]], the service was responsible for overall direction and the identification of foreign agents, while Special Branch provided the manpower for the investigation of their affairs, arrest and interrogation.<ref>{{Cite news|url=https://www.Telegraph.co.uk/news/uknews/1497979/End-for-Special-Branch-after-122-years.html |archive-url=https://ghostarchive.org/archive/20220111/https://www.Telegraph.co.uk/news/uknews/1497979/End-for-Special-Branch-after-122-years.html |archive-date=11 January 2022 |url-access=subscription |url-status=live|title=End for Special Branch after 122 years|website=www.Telegraph.co.uk|date=9 September 2005|publisher=The Telegraph|access-date=21 November 2018}}{{cbignore}}</ref>

On the day after the declaration of the First World War, the Home Secretary, [[Reginald McKenna]], announced that "within the last twenty-four hours no fewer than twenty-one spies, or suspected spies, have been arrested in various places all over the country, chiefly in important military or naval centres, some of them long known to the authorities to be spies".<ref>{{Cite Hansard|speaker=[[Reginald McKenna]]|position=Home Secretary|date=5 August 1914|title=Aliens Restriction Bill|url=https://api.parliament.uk/historic-hansard/commons/1914/aug/05/aliens-restriction-bill|house=[[House of Commons]]|column=1985}}</ref> These arrests have provoked recent historical controversy.  According to the official history of MI5, the actual number of agents identified was 22, and Kell had started sending out letters to local police forces on 29 July, giving them advance warning of arrests to be made as soon as war was declared.  [[Portsmouth Constabulary]] jumped the gun and arrested one on 3 August, and not all of the 22 were in custody by the time that McKenna made his speech, but the official history regards the incident as a devastating blow to [[Imperial Germany]], which deprived them of their entire spy ring, and specifically upset the Kaiser.<ref>{{Cite book|first=Christopher|last=Andrew|title=The Defence of the Realm: The Authorized History of MI5|publisher=Allen Lane|year=2009|pages=49–52}}</ref>

In 2006, his article 'Entering the Lists' was published in the journal ''Intelligence and National Security'', outlining the products of his research into recently opened files.<ref>{{Cite journal|first=Nicholas|last=Hiley|title=Entering the Lists: MI5's great spy round-up of August 1914|journal=Intelligence and National Security|volume=21|issue=1|year=2006|pages=46–76|doi=10.1080/02684520600568303|s2cid=154556503}}</ref>  Hiley was sent an advance copy of the official history, and objected to the retelling of the story.  He later wrote another article, 'Re-entering the Lists', which asserted that the list of those arrested published in the official history<ref>{{Cite book|first=Christopher|last=Andrew|title=The Defence of the Realm: The Authorized History of MI5|publisher=Allen Lane|year=2009|pages=873–875}}</ref> was concocted from later case histories.<ref>{{Cite journal|first=Nicholas|last=Hiley|title=Re-entering the Lists: MI5's Authorized History and the August 1914 Arrests|journal=Intelligence and National Security|volume=25|issue=4|year=2010|pages=415–452|doi=10.1080/02684527.2010.537022|s2cid=153404992}}</ref>