On July 25, 1939, before the war began, the Polish intelligence (Section 2 of the General Staff) provided Great Britain and France with one copy each (with necessary documents) of the German coding machine “Enigma” that allowed to read the secret German messages. A team of Polish cryptologists was evacuated to France, later on to England, where a special center for monitoring and decoding was organized in Bletchley Park. The Polish “Enigma” played a significant role, especially during the Battle of Britain, Battle of the Atlantic and the invasion of the continent in 1944. Other Polish scientists and technicians evacuated to England have to be mentioned as well. The electronics specialists helped with creating the submarine detection system (HFDF – High Frequency Direction Finding). The Polish engineers constructed the reversible tank periscope and an anti-aircraft cannon, with tens of thousands of which the British troops were equipped.
Due to the impossibility of forming regular troops in the occupied Poland, a very important role in the Polish contribution to the anti-Nazi alliance played the intelligence which had a lot of experience in the territory of Germany from before war. During the conflict the Polish intelligence based on two centers: Section 2 of the Commander-in-Chief Staff, operating mainly in Western Europe and North Africa, and Section 2 of the AK Commanding Officer that worked mainly home and in Germany. Section 2 in London was the coordinator of all and had close contacts with correspondent British services, including Special Operations Executive (SOE) that dealt with intelligence and sabotage in occupied Europe. In August 1941 there was an agreement signed with the intelligence of the United States (OCI, later OSS). For some time in 1942 the AK intelligence had direct radio connection with the Red Army. Before that and later on, a lot of information from the Polish intelligence reached Moscow with the help of the British. The relations with the Allies were very important, because the Polish army could not use all the information gathered because of the limited own potential.
The intelligence commanded directly from London created – starting in September 1940 – a lot of posts, a network of which covered practically entire Western and Southern Europe and North Africa. The greatest and the most important was the network in France (Agency “F”, later “F2”), that amounted to more than 2500 agents and only in the years 1940-1942 provided the center in London with more than 5200 reports. In 1944 the working in Paris network “Interallie” focused on the issues related to the invasion. There also existed the networks in Denmark, Belgium, the Netherlands, Sweden, Switzerland, Spain, Portugal, Greece, Palestine, Italy, in the Balkans and the Baltic states. Information sent by the network of the Agency “AFR” played an important role in planning the allied attack on the North Africa (Operation “Torch”, December 1942). In France the intelligence network was closely related to a wider Polish conspiracy activity that had also subversion and propaganda tasks (Polska Organizacja Walki o Niepodległość – Polish Organization of Fight for Independence, aka “Monika”).
The first intelligence structures in the occupied Polish territories emerged in the autumn of 1939, parallel in the framework of the ZWZ staff and upon individual initiatives. Of the latter ones the most important one is the organization “Muszkieterzy” (the Musketeers). The proper development of the intelligence activity began after the fall of France when it was realized that the war was going to last longer than expected. Section 2 was an extended structure with all the departments and services existing in military intelligence, both in the center in Warsaw, and in the AK regions and districts. It is estimated that within their framework some 15 000 people worked, and an important role was played by the employees of the post offices and railways. One of the most important elements were the posts working in Germany (general codename “Stragan” or the “Stall”), located (among other places) in Berlin, Hamburg, Cologne, Wienna, Konigsberg, Wroclaw (Breslau), and Szczecin (Stettin). The offensive intelligence of the “Stragan” (codename “Lombard”, or the “Pawnshop”) undertook also the sabotage actions, like bomb attempts. After the outbreak of the Soviet-German war, the intelligence in the East expanded (codename “Pralnia” or “Laundry”) by organizing posts in Smolensk, Kharkiv, Riga and Daugavpils. In the spring of 1941 the Polish intelligence sent to Moscow via London some comprehensive reports on the German invasion plans.
The most spectacular achievement of the AK intelligence was a thorough study of the research center and factory in Pennemunde, where V1 and V2 missiles were produced. The first information was obtained in the autumn 1942 and in March 1943 a detailed report was sent to London. This allowed the British to conduct a massive bomb attack (the night from August 17 to 18, 1943) which for many months stopped the Wunderwaffe (Wonderful Weapon) construction plans. In 1944 the AK intelligence captured a missile that had not exploded during the drill and sent its parts to London. Quite a role played the data on localization of gasoline factories (operation “Synteza”, or the “Syntesis”) and the military facilities in Germany and Poland. The information on concentration and death camps was also sent. The materials sent by the Poles were very much appreciated by the partners. In the Intelligence Service evaluations it can be read that “the Polish intelligence provided a lot of very valuable information” (first half-year 1942), the estimations delivered by the AK “belong to the most precious ones that we get” (June 1944).
In total, from the second half of 1940 to the end of 1943 (the data for the later period is missing) from the network of the Polish intelligence more than 26 000 reports and a few thousand decoded German messages were delivered to the Allies.