Main Intelligence Directorate (Soviet Union)

Main Intelligence Directorate (Гла́вное разве́дывательное управле́ние), abbreviated GRU (ГРУ), was the foreign military intelligence agency of the Soviet Army General Staff of the Soviet Union.

History
The GRU's first predecessor in Russia formed on October 21, 1918 under the sponsorship of Leon Trotsky, then the civilian leader of the Red Army; it was originally known as the Registration Agency (Registrupravlenie, or RU). Simon Aralov was its first head. In his history of the early years of the GRU, Raymond W. Leonard writes:

As originally established, the Registration Department was not directly subordinate to the General Staff (at the time called the Red Army Field Staff – Polevoi Shtab). Administratively, it was the Third Department of the Field Staff's Operations Directorate. In July 1920, the RU was made the second of four main departments in the Operations Directorate. Until 1921, it was usually called the Registrupr (Registration Department). That year, following the Soviet–Polish War, it was elevated in status to become the Second (Intelligence) Directorate of the Red Army Staff, and was thereafter known as the Razvedupr. This probably resulted from its new primary peacetime responsibilities as the main source of foreign intelligence for the Soviet leadership. As part of a major re-organization of the Red Army, sometime in 1925 or 1926 the RU (then Razvedyvatelnoe Upravlenye) became the Fourth (Intelligence) Directorate of the Red Army Staff, and was thereafter also known simply as the "Fourth Department." Throughout most of the interwar period, the men and women who worked for Red Army Intelligence called it either the Fourth Department, the Intelligence Service, the Razvedupr, or the RU. […] As a result of the re-organization [in 1926], carried out in part to break up Trotsky's hold on the army, the Fourth Department seems to have been placed directly under the control of the State Defense Council (Gosudarstvennaia komissiia oborony, or GKO), the successor of the  RVSR. Thereafter its analysis and reports went directly to the GKO and the Politburo, apparently even bypassing the Red Army Staff. The GRU had the task of handling all military intelligence, particularly the collection of intelligence of military or political significance from sources outside the Soviet Union. It operated residencies all over the world, along with the SIGINT (signals intelligence) station in Lourdes, Cuba, and throughout the former Soviet-bloc countries, especially in Lithuania, Latvia, and Estonia.

The first head of the 4th Directorate was Janis Karlovich Berzin, a Latvian Communist and former member of the Cheka, who served until 1935 and again in 1937. He was arrested (May 1938) and subsequently liquidated (July 1938) during Joseph Stalin's Great Purge.

The GRU was known in the Soviet government for its fierce independence from the rival "internal intelligence organizations", such as the Main Directorate of State Security (GUGB), State Political Directorate (GPU), MGB, OGPU, NKVD, NKGB, KGB and the First Chief Directorate (PGU). At the time of the GRU's creation, Lenin infuriated the Cheka (the predecessor of the KGB) by ordering it not to interfere with the GRU's operations.

Nonetheless, the Cheka infiltrated the GRU in 1919. That worsened a fierce rivalry between the two agencies, which were both engaged in espionage. The rivalry became even more intense than that between the Federal Bureau of Investigation and Central Intelligence Agency in the US.

The existence of the GRU was not publicized during the Soviet era, but documents concerning it became available in the West in the late 1920s, and it was mentioned in the 1931 memoirs of the first OGPU defector, Georges Agabekov, and described in detail in the 1939 autobiography (I Was Stalin's Agent) of Walter Krivitsky, the most senior Red Army intelligence officer ever to defect. It became widely known in Russia, and in the West outside the narrow confines of the intelligence community, during perestroika, in part thanks to the writings of "Viktor Suvorov" (Vladimir Rezun), a GRU officer who defected to Great Britain in 1978 and wrote about his experiences in the Soviet military and intelligence services. According to Suvorov, even the General Secretary of the Communist Party of the Soviet Union, when entering the GRU headquarters, needed to go through a security screening.

SATCOM
During the Cold War, the Sixth Directorate was responsible for monitoring Intelsat communication satellites traffic.

North Korea
GRU Sixth Directorate officers reportedly visited North Korea following the capture (January 1968) of the USS Pueblo, inspecting the vessel and receiving some of the captured equipment.

Head of USSR's GRU

 * Semyon Aralov, November 1918 – July 1919
 * Sergei Gusev, July 1919 – January 1920
 * Georgi Pyatakov, January 1920 – February 1920
 * Vladimir Aussem, February 1920 – August 1920
 * Yan Lentsman, August 1920 – April 1921
 * Arvid Zeybot, April 1921 – March 1924
 * Yan Berzin, 1924 – April 1935
 * Semyon Uritsky, April 1935 – July 1937
 * Yan Berzin, July 1937 – August 1937
 * Alexander Nikonov, August 1937 – August 1937
 * Semyon Gendin, September 1937 – October 1938
 * Alexander Orlov, October 1938 – April 1939
 * Ivan Proskurov, April 1939 – July 1940
 * Filipp Golikov, July 1940 – October 1941
 * Alexei Panfilov, October 1941 – November 1942
 * Ivan Ilyichev, November 1942 – June 1945
 * Fyodor Fedotovich Kuznetsov, June 1945 – November 1947
 * Nikolai Trusov, September 1947 – January 1949
 * Matvei Zakharov, January 1949 – June 1952
 * Mikhail Shalin, June 1952 – August 1956
 * Sergei Shtemenko, August 1956 – October 1957
 * Mikhail Shalin, October 1957 – December 1958
 * Ivan Serov, December 1958 – February 1963
 * Pyotr Ivashutin, March 1963 – July 1987
 * Vladlen Mikhailov, July 1987 – October 1991

Defectors

 * Whittaker Chambers, an American journalist and ex-GRU agent who broke with Communism in 1938
 * Ismail Akhmedov, a Lieutenant-Colonel of the GRU, who defected to Turkey in 1942 . At the end of World War II, the Turks revealed Akhmedov to the Allies, and in 1948 he was interviewed by the first secretary at the British Consulate in Istambul, in reality the local station chief of the SIS and a Soviet mole, Kim Philby.
 * Iavor Entchev, a communist member of GRU; defected to United States during the Cold War.
 * Igor Gouzenko, a GRU cipher clerk who defected in Canada in 1945.
 * Walter Krivitsky, a GRU defector who predicted that Joseph Stalin and Adolf Hitler would conclude a Nazi-Soviet non-aggression pact, found dead in 1941.
 * Stanislav Lunev, a GRU intelligence officer who defected to U.S. authorities in 1992.
 * Oleg Penkovsky, a GRU officer who played an important role during the Cuban Missile Crisis.
 * Dmitri Polyakov, a high-ranking GRU officer who volunteered to spy for the FBI in 1962.
 * Juliet Poyntz, an American communist and founding member of the Communist Party of the United States, allegedly kidnapped and killed in New York in 1937 by NKVD agents for an attempt to defect.
 * Ignace Reiss, a GRU defector who sent a letter of defection to Stalin in July 1937, found dead in September 1937.
 * Viktor Suvorov (pseudonym of Vladimir Bogdanovich Rezun), a GRU officer who defected to the SIS with his wife (also a GRU officer) in Geneva in 1978.
 * Kaarlo Tupmi, an illegal GRU officer turned double agent by the FBI in Milwaukee, Wisconsin in 1959.

Agents

 * Stig Bergling
 * Joseph Milton Bernstein
 * Eugene Franklin Coleman
 * Desmond Patrick Costello (alleged)
 * Klaus Fuchs
 * Harold Glasser
 * Tanner Greimann
 * Rudolf Herrnstadt
 * Arvid Jacobson
 * Gerhard Kegel
 * Mary Jane Keeney and Philip Keeney
 * Tadeusz Kobylański
 * George Koval, a scientist who stole atomic secrets from the Manhattan Project.
 * Ursula Kuczynski
 * Stefan Litauer
 * Robert Osman
 * Ward Pigman
 * Adam Priess
 * Alexander Radó
 * Vincent Reno
 * Elie Renous
 * William Spiegel
 * Lydia Stahl
 * Irving Charles Velson, Brooklyn Navy Yard; American Labor Party candidate for New York State Senate
 * Stig Wennerström

"illegals"

 * Boris Bukov RU RKKA officer
 * Yakov Grigorev
 * Vladimir Kvachkov
 * Hede Massing
 * Richard Sorge
 * Moishe Stern
 * Joshua Tamer
 * Alfred Tilton
 * Alexander Ulanovsky
 * Ignacy Witczak

Naval agents

 * Jack Fahy (Naval GRU), Office of the Coordinator of Inter-American Affairs; Board of Economic Warfare; United States Department of the Interior
 * Edna Patterson Naval GRU, served in US August 1943 to 1956