Battle of Kursk guns and mortars. In 1943 an offensive by the Soviet Central, Bryansk and Western Fronts against Army Group Centre was abandoned shortly after it began in early March, when the southern flank of the Central Front was threatened by Army Group South. Soviet intelligence received information about German troop concentrations spotted at Orel and Kharkov, as well as details of an intended German offensive in the Kursk sector through the Lucy spy ring in Switzerland. The Soviets verified the intelligence via their spy in Britain, John Cairncross, at the Government Code and Cypher School at Bletchley Park, who clandestinely forwarded
Battle of Kursk defensive, yet they did enough to stop a German breakthrough. On the evening of 12 July, Hitler summoned Kluge and Manstein to his headquarters at Rastenburg in East Prussia. Two days earlier, the Western Allies had invaded Sicily. The threat of further Allied landings in Italy or along southern France made Hitler believe it was essential to move forces from Kursk to Italy and to discontinue the offensive. Kluge welcomed the news, as he was aware that the Soviets were initiating a massive offensive against his sector, but Manstein was less welcoming. Manstein's forces had just spent a week fighting