MI6 was eclipsed in terms of intelligence by other initiatives. These were, in general terms:
The massive cryptology effort undertaken by the government and the cryptography school (CS), which was the office responsible for the interception and decryption of foreign communications based at Bletchley Park.
The extensive operation of the "deception" system of MI5 to give misleading information to the Germans.
The work of the photographic unit of recognition. The operation of MI6 was also affected by highly questionable decisions regarding operations, with an increase in risk situations for its own agents. MI6's most famous operation during the war was precisely a failure, known as the Venlo Incident (the Dutch city where it happened), where MI6 was tricked by agents of the German secret service, the Abwehr, who introduced themselves as army officers involved in a plot against Hitler.
In a series of meetings between the MI6 agents and the supposed conspirators, the plans of the German counterintelligence, in the hands of the SS, were to kidnap the MI6 negotiators, but they did not have the expected success due to the presence of the Dutch police, but in a meeting without the presence of the police, two MI6 agents were kidnapped by the SS. This great mistake significantly discredited the reputation of MI6. During the Second World War, the primitive SIS was nominally transformed into "MI6" when, under reorganization of military intelligence, the SIS became Section VI of Military Intelligence (Military Intelligence).
Despite the difficulties at the beginning of the war, MI6 recovered and developed important operations in occupied Europe and in the Far East and Far East where it operated under the name of "interservice deck cover department" (ISLD) . One of the main functions of MI6 during the war was to control the wireless communications systems and Ultra its great success to decipher the Enigma code used by the German Navy. (GC & CS).
