Military intelligence on the V-1 and V-2 weapons developed by the Germans for attacks on the United Kingdom during the Second World War was important to countering them. Intelligence came from a number of sources and the Anglo-American intelligence agencies used it to assess the threat of the German V-weapons. The activities included use of the Double Cross System for counter-intelligence and the British (code named) "Big Ben" project to reconstruct and evaluate German missile technology for which Denmark, Poland, Luxembourg, Sweden, and the USSR provided assistance.German counter-intelligence ruses were used to mislead the Allies about V-1 launch sites and the Peenemünde Army Research Center which were targeted for attacks by the Allies. The Polish resistance Home Army (Armia Krajowa), which conducted military operations against occupying German forces, was also heavily involved in intelligence work. This included operations investigating the German Wunderwaffe: the V-1 flying bomb and the V-2 rocket. British intelligence received their first Polish report regarding the development of these weapons at Peenemünde in 1943.FOOTNOTE: Regarding the "widespread conviction" and Wojewódzki (pgs 18, 252) claim that : Polish authorities in London received despatches and reports on the subject of Peenemünde as early as 1942, the archives of the VIth Bureau that remained in Polish hands after the war and which, as of 1984, were to be found complete in the Polish Underground Movement (1939–45) Study Trust in London. Among them is "not a single document from 1942 concerning the V-1 and the V-2, nor has any been entered in the day-book of the VIth Bureau", and the lack of documentation regarding the claim was confirmed by Colonel Protasewicz and Lieutenant Colonel Bohdan Zielinski, head of the Bureau of Military Studies in the Home Army Intelligence in Warsaw 1943-44. (en)