Operation Sea Lion, also written as Operation Sealion, was Nazi Germany's code name for the plan for an invasion of the United Kingdom during the Battle of Britain in the Second World War. Following the Fall of France, Adolf Hitler, the German Führer and Supreme Commander of the Armed Forces, hoped the British government would seek a peace agreement and he reluctantly considered invasion only as a last resort if all other options failed.
The Office of Strategic Services (OSS) was a wartime intelligence agency of the United States during World War II, and a predecessor to the Central Intelligence Agency (CIA). The OSS was formed as an agency of the Joint Chiefs of Staff (JCS) to coordinate espionage activities behind enemy lines for all branches of the United States Armed Forces. Other OSS functions included the use of propaganda, subversion, and post-war planning. On December 14, 2016, the organization was collectively honored with a Congressional Gold Medal.
Ultra was the designation adopted by British military intelligence in June 1941 for wartime signals intelligence obtained by breaking high-level encrypted enemy radio and teleprinter communications at the Government Code and Cypher School (GC&CS) at Bletchley Park. Ultra eventually became the standard designation among the western Allies for all such intelligence. The name arose because the intelligence obtained was considered more important than that designated by the highest British security classification then used and so was regarded as being Ultra secret. Several other cryptonyms had been used for such intelligence.
The Double-Cross System or XX System was a World War II counter-espionage and deception operation of the British Security Service. Nazi agents in Britain – real and false – were captured, turned themselves in or simply announced themselves, and were then used by the British to broadcast mainly disinformation to their Nazi controllers. Its operations were overseen by the Twenty Committee under the chairmanship of John Cecil Masterman; the name of the committee comes from the number 20 in Roman numerals: "XX".
Wilhelm Franz Canaris was a German admiral and chief of the Abwehr, the German military intelligence service, from 1935 to 1944. Initially a supporter of Adolf Hitler, by 1939 he had turned against the regime. During World War II, he was among the military officers involved in the clandestine opposition to Nazi Germany leadership. He was executed in Flossenbürg concentration camp for high treason as the Nazi regime was collapsing.
The Security Service, also known as MI5, is the United Kingdom's domestic counter-intelligence and security agency and is part of its intelligence machinery alongside the Secret Intelligence Service (MI6), Government Communications Headquarters (GCHQ) and Defence Intelligence (DI). MI5 is directed by the Joint Intelligence Committee (JIC), and the service is bound by the Security Service Act 1989. The service is directed to protect British parliamentary democracy and economic interests, and counter terrorism and espionage within the UK.
The Venlo incident was a covert German Sicherheitsdienst operation on 9 November 1939, in the course of which two British Secret Intelligence Service agents were captured five meters (16 ft) from the German border, on the outskirts of the Dutch town of Venlo.
Walter Friedrich Schellenberg was a German SS functionary during the Nazi era. He rose through the ranks of the SS, becoming one of the highest ranking men in the Sicherheitsdienst (SD) and eventually assumed the position as head of foreign intelligence for Nazi Germany following the abolition of the Abwehr in 1944.
Elyesa Bazna, sometimed known as Iliaz and Ilyaz Bazna, was a secret agent for Nazi Germany during World War II, operating under the code name Cicero.
Operation Green often also referred to as Case Green or Plan Green, was a full-scale operations plan for a Nazi German invasion of Ireland in support of Operation Sea Lion, the invasion of the United Kingdom, during World War II. Despite its detailed nature, Operation Green is thought to have been designed only as a credible threat, a feint, not an actual operation. Plan W, a planned occupation of all of the Free State by the British Armed Forces, was drafted by the British military in secret liaison with the Irish government to counteract any German invasion.
Reinhard Gehlen was a German lieutenant-general and intelligence officer. He was chief of the Wehrmacht Foreign Armies East military intelligence service on the eastern front during World War II, spymaster of the CIA-affiliated anti-Communist Gehlen Organisation (1946–56) and the founding president of the Federal Intelligence Service of West Germany (1956–68) during the Cold War. He was an avid Nazi, as recently released National Security Archive documents confirm.
William G. Sebold was a United States citizen who was coerced into becoming a spy when he visited Germany after being pressured by several high-ranking Nazi members. He informed the American Consul General in Cologne before leaving Germany and became a double agent for the FBI. With the assistance of another German agent, Fritz Duquesne, he recruited 33 agents that became known as the Duquesne Spy Ring. In June 1941, the Federal Bureau of Investigation arrested all of the agents. They were convicted and sentenced to a total of 300 years in prison.
Franz Alfred Six was a Nazi official, promoter of the Holocaust and convicted war criminal. He was appointed by Reinhard Heydrich to head department Amt VII, Written Records of the Reichssicherheitshauptamt (RSHA). In 1940, he was appointed to direct state police operations in an occupied Great Britain following invasion.
The Sonderfahndungsliste G.B. was a secret list of prominent British residents to be arrested, produced in 1940 by the SS as part of the preparation for the proposed invasion of Britain codenamed Unternehmen Seelöwe. After the war, the list became known as The Black Book.
Conrad Fulke Thomond O'Brien-ffrench, Marquis de Castelthomond, was a distinguished British Secret Intelligence Officer, Captain in the Tipperary Rangers of the Royal Irish Regiment and 16th The Queen's Lancers in World War I, and Mountie for the Royal Northwest Mounted Police. He was also an accomplished artist, linguist, mountaineer, skier, and author.
The Abwehr was the German military intelligence service for the Reichswehr and Wehrmacht from 1920 to 1945. Despite the fact that the Treaty of Versailles prohibited the Germans altogether from establishing an intelligence organization of their own, they formed an espionage group in 1920 within the Ministry of Defense, calling it the Abwehr. The initial purpose of the Abwehr was defense against foreign espionage—an organizational role which later evolved considerably. Under General Kurt von Schleicher the individual military services' intelligence units were combined and, in 1929, centralized under his Ministry of Defense, forming the foundation for the more commonly understood manifestation of the Abwehr.
Operation Long Jump was an alleged German plan to simultaneously assassinate Joseph Stalin, Winston Churchill, and Franklin Roosevelt, the "Big Three" Allied leaders, at the 1943 Tehran Conference during World War II. The operation in Iran was to be led by SS-Obersturmbannführer Otto Skorzeny of the Waffen SS. A group of agents from the Soviet Union, led by Soviet spy Gevork Vartanian, uncovered the plot before its inception and the mission was never launched. The assassination plan and its disruption has been popularized by the Russian media with appearances in films and novels.
Richard Henry Stevens was a major in the British Indian Army and from 1939 Head of the Passport Control Office (PCO) of the British Secret Intelligence Service in the Netherlands. His name is closely associated with the Venlo Incident in 1939.
The Secret Intelligence Service (SIS), commonly known as MI6, is the foreign intelligence service of the government of the United Kingdom, tasked mainly with the covert overseas collection and analysis of human intelligence (HUMINT) in support of the UK's national security. SIS is a member of the country's intelligence community and its Chief is accountable to the country's Foreign Secretary.
Ludwig Carl Moyzisch was a diplomatic attaché of the Nazi Germany Embassy in Ankara, Turkey in 1943. Under this cover, he led in Turkey the work of the German secret services, including Elyesa Bazna, codename 'Cicero'. Moyzisch wrote the book Operation Cicero in part to explain his role and activities working for the Sicherheitsdienst (SD). The book was subsequently adapted into the film 5 Fingers, starring James Mason as the spy.
