On 13 July 1943, the largest tank battle in history came to an when the Russian Army repulsing the German offensive. Both Germany and Russia had concentrated their forces near the city of Kursk in western Russia. The Soviet Union held a 150-mile-wide pocket into German lines. The German attack began on 5 Jul with 38 divisions of which half were tanks moving from south and the north. The Soviets had better tanks and air support by this time, unlike previous battles. The fighting was bitter and intense but the Soviet antitank artillery managed to damage or destroy nearly 40 percent of the German armor. Some of the tanks destroyed were the newer class Mark VI Tiger tanks. After six days of warfare, German General Field Marshal Gunther von Kluge called off the offensive. The Germans retreated to their original positions by 23 Jul making it a decisive victory for the Russians, though a very costly one.