Case Blue

Operation Blue (German: Fall Blau) was the German Wehrmacht's codename for the 1942 summer offensive. It led to the Battle of Voronezh, Battle of Stalingrad, and the Battle of the Caucasus. It was originally intended to be called Operation Siegfried, after a legendery Teutonic hero. However, Adolf Hitler, recalling the last grandiosely named offensive operation in Russia, Barbarossa, and its results, which had fallen short of German expectations, settled on the more modest name of Blue.

The Red Army defeated the Wehrmacht at Stalingrad by conducting Operation Uranus and Operation Saturn.

  to 7 July 1942

  to 22 July 1942

  to 1 August 1942

  to 18 November 1942

Army Group South was selected for a sprint forward through the southern Russian steppes into the Caucasus to capture vital oil fields of the Caucasus, then belonging to the Soviet Union. The summer offensive was code-named Fall Blau ("Case Blue" - German military operations were 'cases', or solutions, to problems). It was to include the 6th and 17th Armies and the 4th and 1st Panzer Armies. In 1941, Army Group South had conquered Ukraine, and was positioned at the area of the planned offensive.

General situation before the German Offensive

Operation Blue: German advances from 7 May 1942 to 18 November 1942.

On 22 June 1941, German troops advanced across the Russian border and buffer zones, commencing Operation Barbarossa. Barbarossa''s objective was to take control of several key Russian areas, the main including the Ukraine, Caucasus area, Russian and free Baltic states, and the Moscow metropolitan area. By 9 September 1941, German troops had eliminated resistance in Kiev, taken a firm hold of the Ukraine (well over 60% of ethnic Ukraine population), secured several Baltic states, and advanced to within 300 km of Moscow and 100 km of Leningrad and Kharkov.

Strong communications, sufficient initial supply of basic resources (fuel, clothing, food), technological superiority and organized air superiority led to a powerful German surge during the initial months following June 1941. Factors that led to the formation of Operation Blue were:

1. The success of the Sixth Army and other advanced units across much of Southern Russia (Ukraine). 2. Control of Odessa and Kiev as auxiliary points for air and naval units. 3. Optimal geographic conditions for the several Panzer and motorized divisions in the South (steppe conditions through Stalingrad deep into Asia). 4. Necessity to capture valuable crude oil fields near the Soviet city of Baku, now the capital of Azerbaijan, to supply other motorized units throughout the entire German army. 5. Capture the final components of industrialized West Russia, realistically defeating Russia (combined with other projected successes), and completing Operation Barbarossa.

The German Offensive

The German plan was a three pronged attack in Southern Russia. The 4th Panzer Army commanded by Hermann Hoth (transferred from Army Group North) and the 2nd Army supported by the 2nd Hungarian Army would attack from Kursk to Voronezh and continue the advance to anchor their left wing around the Volga River. The 6th Army, commanded by Friedrich Paulus, would attack from Kharkov and move in parallel with 4th Panzer Army to reach the River Volga. The 1st Panzer Army would strike towards the lower Don River, flanked on its right by the 17th Army. These movements were expected to result in a series of great encirclements of Soviet troops.

The Soviets did not know where the main German offensive of 1942 would come. Stalin was convinced that the German objective of 1942 would be Moscow and over 50% of all Red Army troops were deployed in the Moscow region. Only 10% of Russian troops were deployed in Southern Russia.

On 28 June 1942, the German offensive began. Everywhere the Russians fell back as the Germans sliced through the Russian defenses. By 5 July, forward elements of 4th Panzer Army reached the Don River near Voronezh and became embroiled in a bitter battle to capture the city. The Russians, by tying down 4th Panzer Army, gained vital time to reinforce their defenses. The Russians for the first time in the war were not fighting to hold hopelessly exposed positions but were retreating in good order. As German pincers closed in they only found stragglers and rearguards. This only served to convince Hitler that the Russians were down to the last of their manpower reserves.

Angered by the delays and believing the Soviet center had fallen apart Hitler made a series of changes to Operation Blue. Hitler re-organized Army Group South to two smaller Army Groups, Army Group A, under the command of Paul Ludwig Ewald von Kleist, which now included the German 17th Army and the German 1st Panzer Army and Army Group B, under the command of Maximilian von Weichs, which included German 2nd Army, 6th Army, the 4th Panzer Army and two Italian and Hungarian Armies. Army Group A was tasked with advancing on the Caucasus and capturing the vital oil fields around Baku. Army Group B was tasked with the drive for Stalingrad.

The success of the initial advance of the 6th Army was such that Hitler ordered the 4th Panzer Army south to assist 1st Panzer Army and force a crossing of the lower Don River. This sudden redeployment of an entire Army caused a massive logistical problem, as the road networks in this part of Russia was sub-standard. The resulting traffic jams caused delays to both Army Group A and B's progress. It also removed vital tank support from the 6th Army, slowing its advance and giving the Russians further time to consolidate their positions.

Army Group A captured Rostov on 23 July 1942. But the Russians fought a skillful rearguard action which embroiled the Germans in heavy urban fighting to take the city. This allowed the main Russian formations to escape encirclements. With the River Don crossing secured and with the 6th Army's advance flagging Hitler send the 4th Panzer Army back to join up with 6th Army.

In late July, 6th Army resumed its offensive and by 10 August 1942 6th Army cleared Russian presence from the west bank of the River Don. However, the Russians held out in some areas further delaying 6th Army's march east. In contrast, Army Group A after crossing the River Don on 25 July had fanned out on a broad front. The German 17th Army swung west towards the Black Sea, the 1st Panzer Army attacked towards the south and east sweeping through country largely abandoned by the Russians. On 9 August 1st Panzer Army reached the foothills of the Caucausian mountains, having advanced more than 300 miles.

6th Army crossed the river Don on 21 August, allowing Army Group B to establish a defensive line on the Don bend using the Hungarian, Italian and two Romanian armies. 6th Army began advancing on Stalingrad. With the city within reach from forward air bases, Luftwaffe bombers attacked the city killing over 40,000 people and turning much of the city into rubble. The ground attack on Stalingrad was two-pronged, with the 6th Army advancing from the North while the 4th Panzer Army advanced from the South. Between these armies and in the area from Rover Don to River Volga, a salient had been created. 2 Russian Armies were in the salient and on 29 August 4th Panzer Army mounted a major attack through the salient towards Stalingrad. 6th Army was ordered to do the same but Russian tanks counterattacked against the 6th Army which tied up the 6th Army for 3 vital days enabling the Soviet forces in the salient to escape encirclement and fall back towards Stalingrad.

Georgy Zhukov had assumed command of the Stalingrad front and in early September, he mounted a series of attacks from the North which further delayed the 6th Army's attempt to seize Stalingrad. Meanwhile Soviet forces continued to be sent south to bolster the defense of Stalingrad and to take up positions on the east side of the river Volga. By mid-September, the 6th Army, after neutralizing the Soviet counterattacks, once again resumed the march on Stalingrad. On 13 September the Germans advanced through the southern suburbs of Stalingrad, beginning the Battle of Stalingrad.