In the summer of 1943, instead of a far-reaching offensive on the Eastern Front, the Germans planned only a limited attack at Kursk, which was nevertheless intended to decisively weaken the Red Army. Hitler then wanted to move the most powerful units to the west in order to repel the expected Allied invasion. However, the Soviets turned the front salient around the city of Kursk into a fortress and amassed huge reserves there. After repulsing the German attack, these were to launch an offensive of their own and advance to the borders of the German Reich in 1943. When the German attack began on 5 July 1943, it did not lead to a short and victorious annihilating strike, as Hitler had hoped, but instead initiated the largest battle of the Second World War. It lasted 50 days, led to the clash of around 3.5 million soldiers, 13,000 tanks and self-propelled guns, as well as 8,000 aircraft, and ended with a decisive Soviet victory. Although the Red Army was unable to achieve its strategic objectives in 1943 due to its huge losses, the Wehrmacht was so weakened after the Battle of Kursk that it never regained the initiative on the Eastern Front.