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 to pierce the southern face of the salient. This force would drive north to meet the 9th Army east of Kursk. Von Manstein's main attack was to be delivered by Hoth's 4th Panzer Army, spearheaded by the II SS Panzer Corps under Paul Hausser. The XLVIII Panzer Corps, commanded by Otto von Knobelsdorff, would advance on the left while Army Detachment "Kempf" would advance on the right. The 2nd Army, under the command of Walter Weiss, would contain the western portion of the salient. On 27 April Model met with Hitler to review and express his concern for reconnaissance information