Opening phase The German offensive commenced on 28 June 1942, with Fourth Panzer Army starting its drive towards Voronezh. Due to a chaotic Soviet retreat, the Germans were able to advance rapidly, restoring
Wehrmacht confidence for the upcoming major offensive.
Close air support from the Luftwaffe also played an important role in this early success. It contained the
Red Air Force, through
air superiority operations, and provided interdiction through attacks on airfields and Soviet defence lines. At times, the German air arm acted as a spearhead rather than a support force, ranging on ahead of the tanks and infantry to disrupt and destroy defensive positions. As many as 100 German aircraft were concentrated on a single Soviet division in the path of the spearhead during this phase. General Kazakov, the Bryansk Front's chief of staff, noted the strength and effectiveness of the Axis aviation. Within 26 days, the Soviets lost 783 aircraft from the
2nd,
4th,
5th and
8th Air Armies, compared to a German total of 175. By 5 July, forward elements of Fourth Panzer Army had reached the
Don River near Voronezh and became embroiled in the
battle to capture the city. Stalin and the Soviet command still expected the main German thrust in the north against Moscow, and believed the Germans would turn north after Voronezh to threaten the capital. This assistance was not needed and Kleist later complained that Fourth Panzer Army clogged the roads and that if they had carried on toward Stalingrad, they could have taken it in July. When it turned north again two weeks later, the Soviets had gathered enough forces together at Stalingrad to check its advance.
Army Group A: Caucasus Breaking into the Caucasus armored half-track on the Russian steppe, August 1942 With air support from the Ju 87s of , List's Army Group A recaptured Rostov, the "gate to the Caucasus", on 23 July 1942 relatively easily. The
Luftwaffe had air superiority in the early phase of the operation, which was of great help to the ground forces. With the Don crossing secured and Sixth Army's advance flagging on the Volga front, Hitler transferred the Fourth Panzer Army to Army Group B and sent it back to the Volga. The redeployment used enormous amounts of fuel to transfer the army by air and road. After crossing the Don on 25 July, Army Group A fanned out on a front from the
Sea of Azov to Zymlianskaya (today Zymlyansk). The German Seventeenth Army, along with elements of the Eleventh Army and the Romanian Third Army, manoeuvred west towards the east coast of the Black Sea, while the First Panzer Army attacked to the south-east. The Seventeenth Army made a slow advance but the First Panzer Army had freedom of action. On 29 July the Germans cut the last direct railway between central Russia and the Caucasus, causing considerable panic to Stalin and Stavka, which led to the passing of
Order No. 227 "Not a step back!".
Salsk was captured on 31 July and
Stavropol on 5 August. The length of the German advance created chronic supply difficulties, particularly of petrol; the Black Sea was judged too dangerous and fuel was brought by rail through Rostov or delivered by air, but panzer divisions were sometimes at a standstill for weeks. Even petrol trucks ran out of fuel and oil had to be brought up on camels. With the Soviets often retreating instead of fighting, the number of prisoners fell short of expectations and only 83,000 were taken. As Hitler and OKH began to concentrate on Stalingrad, some of Kleist's mobile forces were diverted. Kleist lost his flak corps and most of the
Luftwaffe supporting the southern front, only reconnaissance aircraft being left behind. The
Voyenno-Vozdushnye Sily (VVS) brought in about 800 bombers, a third of which were operational. With the transfer of air cover and flak units, Soviet bombers were free to harass the German advance. The quality of the Soviet resistance increased, with many of the forces used coming from local levies, who Kleist thought were willing to fight harder for their homeland. German units were especially bogged down by fighting Georgian alpine and mountain troops, who greatly contributed to stalling their advance. The quantity of replacements and supplies the Soviets committed increased, and faced with these difficulties, the Axis advance slowed after 28 August.
Battle for the oilfields In the south-east, the
Wehrmacht headed in the direction of Grozny and
Baku, the other important petroleum centers. More installations and industrial centers fell into German hands, many intact or only slightly damaged during the
Russian retreat. From August–September, the
Taman Peninsula and a part of the
Novorossiysk naval base were captured. The Germans continued towards
Tuapse on the Black Sea coast and in the east
Elista was taken on 13 August. In the south, the German advance was stopped north of Grozny, after taking
Mozdok on 25 August. German paratroopers assisted an
insurgency in Chechnya, operating behind Soviet lines. German mountain troops failed to secure the Black Sea ports and the advance fell short of Grozny as supply difficulties arose once more. The Soviets dug in the 9th and 44th armies of the North Transcaucasian Front along the rocky
Terek River bank in front (north) of the city. The
Luftwaffe was unable to support the German army that far forward and Soviet aviation attacked bridges and supply routes virtually unopposed. The Germans crossed the river on 2 September but made only slow progress. At the beginning of September, Hitler had a major argument with the High Command and specifically List, as he perceived the advance of the German forces as too slow. As a result, Hitler dismissed List on 9 September and took direct command of Army Group A himself. Axis ships transported 30,605 men, 13,254 horses and 6,265 motor vehicles across the Black Sea from Romania, from 1–2 September. With the reinforcements, the Germans captured most of the Black Sea naval bases but were held up at Novorossiysk, where the Soviet 47th Army had prepared for a long siege. The port fell on 10 September, after a four-day battle, the final German victory in the Caucasus. It left the heights south of the port and several coast roads in the hands of 47th Soviet Army. Attempts to push out of Novorossiysk were costly failures and the Axis also failed to break the defences on the coastal plain from Novorossiysk to Tuapse, having only the strength to stabilize the line. Romanian Army losses were particularly high and the Romanian 3rd Mountain Division was nearly wiped out by a Soviet counter-attack from 25–26 September. Further east, the Axis enjoyed greater success and on 1 September, the Germans took (), halfway between Elista and
Astrakhan. During August and September, German patrols raided the railway around
Kizlyar, north-east of Grozny, marking the farthest advance of the German forces towards the Caspian Sea. In the south, the First Panzer Army advance on Grozny was stopped by the Red Army and the
14th Air Army. By late September, supply failures and the resistance of the Red Army slowed the Axis advance. The Germans took Nakchik on 26 October. '' operating a 2 cm anti-aircraft gun in the Central Caucasus near
Teberda, September 1942 On 2 November 1942, Romanian mountain troops () under the command of Brigadier General
Ioan Dumitrache took
Nalchik, the capital of
Kabardino-Balkaria and also the farthest point of Axis advance into the Caucasus. This victory earned the Romanian General the
Knight's Cross of the Iron Cross. Up to 10,000 prisoners were captured in two days, before the advance toward Grozny was stopped again west of the city at
Vladikavkaz. On 5 November, Alagir was seized and the
Alagir–
Beslan–
Malgobek line reached became the farthest German advance in the south. By this time, the gap between Army Groups A and B had left them vulnerable to a counter-offensive. Only the
German 16th Motorized Infantry Division remained inside the gap, guarding the left flank of the First Panzer Army by securing the road towards Astrakhan. On 22 November, after several Soviet counter-attacks, Hitler appointed Kleist as Group commander with orders to hold his position and prepare to resume the offensive if
Stalingrad could be taken.
Luftwaffe oil offensive In the first week of October 1942, Hitler came to recognize that the capture of the Caucasus oil fields was unlikely before winter, which forced the Germans to take up defensive positions. Unable to capture them, he was determined to deny them to the enemy and ordered the (OKL) to inflict as much damage as possible. On 8 October, Hitler called for the air offensive to be carried out no later than 14 October, as he required air assets for a major effort at Stalingrad. As a result, on 10 October 1942, of 4 (4th Air Corps of Fourth Air Fleet) was ordered to send every available bomber against the oilfields at Grozny. Fourth Air Fleet was in poor shape by this time – Richthofen had begun Case Blue with 323 serviceable bombers out of a total of 480. He was now down to 232, of which only 129 were combat ready. Nevertheless, the force could still deliver damaging blows. Attacks on the refineries reminded Richthofen of the attacks on Sevastopol several months earlier. Thick black smoke rose from the refineries to a height of . On 12 October, further raids caused even more destruction. It had been a strategic mistake not to have made greater efforts to hit the oil refineries at Grozny and Baku sooner, as their destruction would have been a greater blow to the Soviets than the loss of Stalingrad, where most of the air fleet was deployed. On 19 November, the Soviet counter-offensive at Stalingrad compelled Richthofen to once more withdraw his units north to the Volga and bring an end to the aerial offensive. Much damage was done at Grozny, but the remaining oilfields were beyond the logistical reach of the German Army as well as of the fighter aircraft of the Luftwaffe. Grozny was within range of German bombers from 4th Air Corps, based near the Terek River. But Grozny and the captured oilfields at Maikop produced only ten per cent of Soviet oil. The main fields at Baku were out of German fighter range. German bombers could have reached them, but it meant flying the most direct, thus most predictable route without protection. In August it might have been possible to carry out these operations owing to the weakness of Soviet air power in the region, but by October it had been considerably strengthened.
Army Group B: Volga Don bend On 23 July, the main body of Army Group B started its advance toward the Don. The Germans met with increasing Soviet resistance from the new Stalingrad Front, with the
62nd and
64th Soviet Armies. On 26 July,
XIV Panzer Corps broke through and reached the Don, where the new
First and
Fourth Tank Armies conducted several futile counter-attacks by inexperienced troops. In the south, Fourth Panzer Army made better progress against
51st Army. After crossing the Don, the Germans advanced on
Kotelnikovo, reaching the town by 2 August. Soviet resistance convinced Paulus that Sixth Army was not strong enough to cross the Don by itself, so he waited for Fourth Panzer Army to fight its way north. On 4 August, the Germans were still from Stalingrad. By 10 August, the Red Army had been cleared from most of the west bank of the Don, but Soviet resistance continued in some areas, further delaying Army Group B. The
Wehrmacht advance on Stalingrad was also impeded by supply shortages caused by the poor state of Soviet roads. The
Luftwaffe sent an ad-hoc force of 300 Ju 52 transport aircraft, enabling the Germans to advance; some bombers were diverted from operations to supply flights under the
Stalingrad Transport Region force. The Soviet defence at the Don forced the Germans to commit more and more troops to an increasingly vulnerable front, leaving few reserves to back up the Axis divisions on either flank. The Soviets made several counter-attacks on the northern flank of Army Group B, between Stalingrad and Voronezh. From 20–28 August, the
63rd Army and the
21st Army counter-attacked near
Serafimovich, forcing the Italian Eighth Army to fall back. The
1st Guards Army attacked near
Novo-Grigoryevskaja, extending its bridgehead. These and several other bridgeheads across the Don, opposed by the Eighth Italian and Second Hungarian armies, were a constant danger. dive bomber over Stalingrad On 23 August, Sixth Army crossed the Don and Army Group B established a defensive line on one of its bends. Sixth Army reached the northern suburbs of Stalingrad later that day, beginning the
Battle of Stalingrad. The Hungarian, Italian and Romanian armies were from Stalingrad, which was in range of forward air bases.
Luftflotte 4 attacked the city, turning much of it to rubble. The Soviets reported that civilian casualties from 23–26 August were 955 dead and 1,181 wounded (a preliminary total; later reports of casualties in the tens of thousands were probably exaggerations). Sixth Army advanced from the north via
Kalach and Fourth Panzer Army came up from the south through Kotelnikovo. In the first few days, the XIV Panzer Corps opened a corridor between the main body of Sixth Army and the northern Stalingrad suburbs at the Volga. In the south, Soviet resistance repulsed the Fourth Panzer Army. On 29 August another attempt was made with Hoth turning his forces west directly through the center of 64th Army. The attack was unexpectedly successful and Fourth Panzer Army got behind 62nd and 64th Armies with the chance to encircle and cut off 62nd Army. Weichs ordered Sixth Army to complete the encirclement; a Soviet counter-attack held up the advance for three days and the Soviets escaped and retreated towards Stalingrad. The rapid German advance caused a slump in morale among the Soviet troops, who retreated in chaos, abandoning the outer defences of the city. After defeating the last Soviet counterattacks, Sixth Army resumed its offensive on 2 September, linking up with Fourth Panzer Army the following day. On 12 September, the Germans entered Stalingrad.
Battle of Stalingrad The advance into Stalingrad against the 62nd Army was carried out by Sixth Army, while Fourth Panzer Army secured the southern flank. The city was a ribbon along the west bank of the Volga, which forced the Germans to conduct a frontal assault, and the ruins of the city gave the defenders an advantage. To counter
Luftwaffe air superiority, the commander of the 62nd Army, General
Vasily Chuikov, ordered his troops to "hug" the Germans, negating German tactical mobility. The
Luftwaffe suppressed Soviet artillery on the east bank of the Volga and caused many casualties during Soviet attempts to reinforce the defenders on the west bank. From mid-September until early November the Germans made three big attacks on the city and ground forward in mutually-costly fighting. By mid-November, the Soviets were penned into four shallow bridgeheads, with the front line only from the river. Anticipating victory, substantial numbers of
Luftwaffe aircraft were withdrawn to the Mediterranean in early November to support the Axis operations in
Tunisia. Sixth Army had captured about 90 percent of the city. On 19 November, the Soviets launched
Operation Uranus, a two-pronged counter-offensive against the flanks of Sixth Army. With the battle for the city and the exhaustion of Fourth Panzer Army, the flanks were mainly guarded by Romanian, Hungarian and Italian soldiers. Third Romanian Army, on the Don River west of Stalingrad, and Fourth Romanian Army, south-east of Stalingrad, had been under constant Soviet attack since September. Third Romanian Army had been transferred from the Caucasus on 10 September to take over Italian positions on the Don, opposite the Soviet bridgeheads. The Romanians were understrength and had only around six
modern anti-tank guns per division. The bulk of the German tank reserve, the
48th Panzer Corps, consisted of about 180 tanks, half being obsolete
Panzer 35(t)s. The two Romanian armies were routed and Sixth Army with parts of Fourth Panzer Army were encircled in Stalingrad. Hitler ordered Sixth Army to remain on the defensive, rather than try to break out. It was intended the army would be supplied by air, but the quantity of supplies necessary was far beyond the ability of the
Luftwaffe to carry. Sixth Army's strength diminished and the Soviets gained the upper hand inside the city. To stabilize the situation on the Eastern Front,
Army Group Don () under Field Marshal
Erich von Manstein was created to fill the gap between Army Groups A and B. On 12 December, a relief operation called
Operation Winter Storm was launched from the South by fresh reinforcements of the 4th Panzer Army. The offensive surprised the Soviets and the Germans were able to penetrate the Soviet line for towards Stalingrad. Despite these gains, the Sixth Army was not allowed to attempt to break out and link up, so this led to nothing. The failure was followed by a siege that lasted for almost two months, during which the Sixth Army was destroyed. ==Aftermath==