MI5 B Branch (1938-1953)

MI5 B Branch was a key investigative branch of MI5 from the 1920s to the 1940s.
==History==
In 1929, an early incarnation of B Branch was responsible for 'investigations and inquiries'.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.127.
Following a 1938 re-organisation, B Branch acquired responsibility for counter-espionage and counter-subversion.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.134.
===Post-1953===
*MI5 B Branch
In Dick White's 1953 re-organisation of the service, B Branch became responsible for personnel and establishments.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.327.
==Organisation==
===Directors===
*Joseph Ball - 1926.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.126.
*Oswald Allen HarkerChapman Pincher, Treachery: Betrayals, Blunders and Cover-Ups: Six Decades of espionage, Mainstream Publishing, 2012, p.98. - c.1929.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.127.
*Guy Liddell - 1939-45Chris Hastings and Fiona Govan, MI6 urged Churchill to nuke Berlin The fear of Germany's V2 rockets in 1944 led Britain to consider the ultimate reprisal, Sunday Telegraph, 1 December 2002.
*Dick White c.1946.Chapman Pincher, Treachery: Betrayals, Blunders and Cover-Ups: Six Decades of espionage, Mainstream Publishing, 2012, p.66.
*John Marriott - C.1951Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.580.
===B1===
Counter-subversion.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.324.
*Roger Hollis - B1 c.1946.Chapman Pincher, Treachery: Betrayals, Blunders and Cover-Ups: Six Decades of espionage, Mainstream Publishing, 2012, p.263.
*Graham Mitchell - B1 c.1949.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.384.
====Bla====
Double agent section.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.248.
*Thomas Argyll Robertson - B1a. c.1941.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.249.
*John MarriotChristopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.285.
*Christopher HarmerChristopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.249.
*Hugh AstorChristopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.249.
*Cyril MillsChristopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.251.
*Charles Cholmondeley.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.285.
*Ronnie ReedChristopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.287.
====B1b====
Analysed Abwehr decrypts and other intelligence related to the double-cross system.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.249.
*Helenus Milmo B1b c.1940.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.250.
*Herbert HartChristopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.250.
*Patrick DayChristopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.250.
====B1d====
London Reception Centre.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.251.
====B1e====
Camp 020 wartime interrogation centre.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.250. Reformed in 1948 to investigate communism in the Civil Service and the professions.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.384.
*Captain Robin Stephens c.1941
*Graham Mitchell - B1e c.1948.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.384.
====B1f or B5(b)====
According to Christopher Andrew, Maxwell Knight's section was became B1F section of B Division in 1938.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.134. However, other sources refer to Knight's wartime section as B5(b).Anthony Masters, The Man who was M: The Life of Maxwell Knight, The real-like spymaster who inspired Ian Fleming, Grafton Books, p.46. 
*Maxwell Knight - B1F c.1939.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.134.
*Bill Younger - Knight's personal assistant.Anthony Masters, The Man who was M: The Life of Maxwell Knight, The real-like spymaster who inspired Ian Fleming, Grafton Books, p.101. 
*John Bingham - Knight's deputy.Anthony Masters, The Man who was M: The Life of Maxwell Knight, The real-like spymaster who inspired Ian Fleming, Grafton Books, p.101. 
*Philip Brocklehurst.Anthony Masters, The Man who was M: The Life of Maxwell Knight, The real-like spymaster who inspired Ian Fleming, Grafton Books, p.101. 
*Norman Himsworth - responsible for supervising anti-communist operations..Anthony Masters, The Man who was M: The Life of Maxwell Knight, The real-like spymaster who inspired Ian Fleming, Grafton Books, p.101. 
*Tony Gillson.Anthony Masters, The Man who was M: The Life of Maxwell Knight, The real-like spymaster who inspired Ian Fleming, Grafton Books, p.101. 
*Rex Land.Anthony Masters, The Man who was M: The Life of Maxwell Knight, The real-like spymaster who inspired Ian Fleming, Grafton Books, p.101. 
*Guy Poston.Anthony Masters, The Man who was M: The Life of Maxwell Knight, The real-like spymaster who inspired Ian Fleming, Grafton Books, p.101. 
*Joan Wheatley.Anthony Masters, The Man who was M: The Life of Maxwell Knight, The real-like spymaster who inspired Ian Fleming, Grafton Books, p.101. 
*Joan Miller.Anthony Masters, The Man who was M: The Life of Maxwell Knight, The real-like spymaster who inspired Ian Fleming, Grafton Books, p.101.
====B1G====
Counter-Spanish espionage.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.261.
====B2====
Counter-espionage.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.324.
*Robert Hemblys-Scales c.1948.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.370.
*Arthur Martin - B2b c.1948.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.370.
*R.T. Reed - B2b c.1952.Chapman Pincher, Treachery: Betrayals, Blunders and Cover-Ups: Six Decades of espionage, Mainstream Publishing, 2012, p.331.
====B3a====
Liased with Security Intelligence Middle East. Responsible for dealing with Zionist terrorism and other Middle Eastern matters.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.352.
===B4===
Responsible for Soviet counter-espionage.Chapman Pincher, Treachery: Betrayals, Blunders and Cover-Ups: Six Decades of espionage, Mainstream Publishing, 2012, p.66. 
*James Robertson - B4, 1946.Chapman Pincher, Treachery: Betrayals, Blunders and Cover-Ups: Six Decades of espionage, Mainstream Publishing, 2012, p.264.
*Kathleen Archer - B4a c.1939.Chapman Pincher, Treachery: Betrayals, Blunders and Cover-Ups: Six Decades of espionage, Mainstream Publishing, 2012, p.66.
*Roger Hollis - B4a(3) c.1939.Chapman Pincher, Treachery: Betrayals, Blunders and Cover-Ups: Six Decades of espionage, Mainstream Publishing, 2012, p.66.
===Other Officers===
*William Alexander - 1919.Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.150.
==Notes==
Category:SpooksCategory:MI5