The Battle of Kursk was a Second World War engagement between German and Soviet forces on the Eastern Front near Kursk (450 kilometres or 280 miles south-west of Moscow) in the Soviet Union during July and August 1943. The German offensive was code-named Operation Citadel (German: Unternehmen Zitadelle) and led to one of the largest armoured clashes in history, the Battle of Prokhorovka. The German offensive was countered by two Soviet counter-offensives, Operation Polkovodets Rumyantsev (Russian: Полководец Румянцев) and Operation Kutuzov (Russian: Кутузов). For the Germans, the battle was the final strategic offensive that they were able to launch on the Eastern Front. Their extensive loss of men and tanks ensured that the victorious Soviet Red Army enjoyed the strategic initiative for the remainder of the war.
The Soviet government had foreknowledge of the German intentions, provided in part by the British intelligence service and Tunny intercepts. Aware months in advance that the attack would fall on the neck of the Kursk salient, the Soviets built a defence in depth designed to wear down the German armoured spearhead. The Germans delayed the offensive while they tried to build up their forces and waited for new weapons, mainly the new Panther tank but also larger numbers of the Tiger heavy tank. This gave the Red Army time to construct a series of deep defensive belts. The defensive preparations included minefields, fortifications, artillery fire zones and anti-tank strong points, which extended approximately 300 km (190 mi) in depth. Soviet mobile formations were moved out of the salient and a large reserve force was formed for strategic counter-offensives.
The Battle of Kursk was the first time in the Second World War that a German strategic offensive was halted before it could break through enemy defences and penetrate to its strategic depths. The maximum depth of the German advance was 8–12 kilometres (5.0–7.5 mi) in the north and 35 kilometres (22 mi) in the south. Though the Red Army had succeeded in winter offensives previously, their counter-offensives following the German attack at Kursk were their first successful strategic summer offensives of the war.