On 12 July, a heavy artillery barrage marked the launching of the offensive. The armies of the
Bryansk Front and the
Western Front attacked along the north and north-east flanks of the 2nd Panzer Army. The Western Front assault was led by the
11th Guards Army under Lieutenant General
Hovhannes Bagramyan, supported by the 1st and 5th Tank Corps. The Soviets attacked with overwhelming numbers. Along one attack sector near Ulianovo, six Soviet rifle divisions attacked two German infantry regiments. At in depth, the German defensive lines were deeper than the Soviets expected. The Soviet spearheads sustained heavy casualties but pushed through and in some areas achieved significant penetration. The defenders were overwhelmed by the afternoon of the first day, with the 11th Guards Army advancing some . The German
5th Panzer Division attempted to fill the breach but they were met by the Soviet supporting armour and were forced back. The initial attacks on the eastern face by the Bryansk Front were less successful. The
61st,
3rd, and
63rd armies advanced respectively. The following day the German
LIII Army Corps counter-attacked and brought the Bryansk Front to a halt. The open terrain favored the longer ranged guns of the Germans. Kluge and Model had anticipated the Soviet attack and were quick to transfer units from the Kursk area to reinforce the defenders. Their timely arrival helped check the Soviet advance. Farther north the 11th Guards Army was forcing its way through the German defences. The Germans lacked the reserves to block these penetrations. With the danger of a breakthrough and subsequent encirclement of their forces, the situation soon became serious for the 2nd Panzer Army. Army Group Centre transferred command of the 2nd Panzer Army to Model by the end of the second day. As Model was already commanding the German 9th Army making the north portion of the Kursk attack, the command transfer meant he was now in command of all German units in the Orel area. of the 2nd Panzer Division near Orel Three days later the second phase of Operation Kutuzov was initiated, with attacks on the German 9th Army by several Soviet armies. The total Soviet troops now engaged in Operation Kutuzov numbered 1,286,049 men supported by 2,409 tanks and 26,379 guns. The Soviets broadened the offensive, adding supporting attacks by the
50th Army to the north of the 11th Guards Army. Between the 50th Army and the
Bryansk Front was a thrust by the 20th Tank Corps aimed at
Bolkhov, along with a push by the Central Front on the south face. To increase the momentum of the attack the Soviets now committed the
3rd Guards Tank Army and
4th Tank Army from the reserves. The 3rd Guards drove straight for Orel, attempting to develop the eastern attack, while the 4th Tank Army drove from the north along the wider breach made by 11th Guards Army. In doing so they threatened to trap the German forces defending the east face of the Orel salient. German defensive efforts were hampered by partisan attacks to their communications and rail supply lines. As Soviet breakthroughs developed the situation for the Germans became serious. The entire 9th Army was threatened with being cut off. Model sent nearly all of his Panzer units to aid the 2nd Panzer Army, whose northern front was about to collapse, while to the north the
4th Army sent down the 253rd Infantry Division. The Germans achieved a temporary stabilization of the front while the 9th Army began to withdraw from their captured ground. The Soviet Central Front followed them hesitantly at first but increased the intensity of their attacks from the ground and the air. On 18 July the 9th Army was back at its starting points of 5 July. A series of engagements developed in the Orel salient between arriving German reserves and Soviet tank formations. Though Hitler forbade retreat, the Soviets gradually gained ground. By 26 July the German troops were forced to desert the Orel base of operations and begin a withdrawal to the Hagen position to the east of Bryansk. With the 11th Guards reaching the outskirts of
Karachev, midway between
Orel and Bryansk, they threatened to cut the main rail line which was the main route of supply. On 29 July Bolkhov was liberated, and on 4 August the struggle for Orel commenced. After one day of hard fighting Orel was taken. With their position untenable, the Germans were forced to evacuate back to prepared positions at the Hagen line. By 18 August Soviet troops had reached the Hagen line east of Bryansk at the base of the Orel salient. With the German defeat the counter-offensive began to grow into a general Soviet offensive. == Contest for air superiority ==