Battle between the Russian and German Empires during World War I
The Battle of Tannenberg, also known as the Second Battle of Tannenberg, was fought between Russia and Germany between 23 and 30 August 1914, the first month of World War I. The battle resulted in the almost complete destruction of the Russian Second Army and the suicide of its commanding general, Alexander Samsonov. A series of follow-up battles (First Masurian Lakes) destroyed most of the First Army.
The battle is particularly notable for fast rail movements by the German Eighth Army, enabling them to concentrate against each of the two Russian armies in turn, first delaying the First Army and then destroying the Second before once again turning on the First days later. It is also notable for the failure of the Russians to encode their radio messages, broadcasting their daily marching orders in the clear, which allowed the Germans to make their movements with the confidence they would not be flanked.
The almost miraculous outcome brought considerable prestige to General (later Field Marshal) Paul von Hindenburg and his rising staff-officer Erich Ludendorff. Although the battle actually took place near Allenstein (Olsztyn), Hindenburg named it after Tannenberg, to the west, in order to avenge the Teutonic Knights' defeat at the First Battle of Tannenberg 500 years earlier.
Background.
Germany entered World War I largely following the Schlieffen Plan. According to Prit Buttar, "In combination with his own strong desire to fight an offensive war featuring outflanking and encircling movements, Schlieffen went on to develop his plan for a sweeping advance through Belgium. In the east, limited German forces would defend against any Russian attack until more forces became available from the west, fresh from victory over the French. The total strength of the fully mobilised German Army in 1914 amounted to 1,191 battalions, the great majority of which would be deployed against France. The Eighth Army in East Prussia would go to war with barely 10 per cent of this total."
The Russian Forces were less prepared than they would have otherwise been thanks to an overestimation of the Russian war machine and a general who was having real problems on Russia's other fronts. General Yakov Grigoryevich Zhilinsky was the man in charge of this attack and had pledged to put 800,000 men in France by the 15th day of mobilization. Of course due to the rushed nature of this attack, the Russian war machine developed numerous cracks and failures as a result of poor communication between the front and command. This lack of communication resulted in orders that would contradict the previous ones and headquarters giving soldiers orders in a hurry. All of this confusion and disorganization severely hampered the General's efforts and progress on the Russian Front stalled.
The French army's Plan XVII at the outbreak of the war involved swift mobilization followed by an immediate attack to drive the Germans from Alsace and Lorraine. If the British Expeditionary Force (BEF) joined in accordance with their Allied treaty, they would fill the left flank. Their Russian allies in the East would have a massive army, more than 95 divisions, but their mobilization would inevitably be slower. Getting their men to the front would itself take time because of their relatively sparse and unreliable railway network (for example, 75% of Russian railways were still single-tracked). Russia intended to have 27 divisions at the front by day 15 of hostilities and 52 by day 23, but it would take 60 days before 90 divisions were in action. Despite their difficulties, the Russians promised the French that they would promptly engage the armies of Austria-Hungary in the south and on day 15 would invade German East Prussia.
According to Prit Buttar, "In addition to the fortifications amongst the Masurian Lake District, the Germans had built a series of major forts around Königsberg in the 19th century and had then modernised them over the years. Similarly, major fortresses had been established along the Vistula, particularly at Thorn (now Toruń). Combined with the flexibility provided by the German railways, allowing General Maximilian von Prittwitz to concentrate against the inner flanks of either Russian invasion force, the Germans could realistically view the coming war with a degree of confidence."
The Russians would rely on two of their three railways that ran up to the border; each would provision an army. The railways ended at the border, as Russian trains operated on a different rail gauge from Western Europe. Consequently, its armies could be transported by rail only as far as the German border and could use Prussian railways only with captured locomotives and rolling stock. The First Army would use the line that ran from Vilnius, Lithuania, to the border southeast of Königsberg. The Second Army railway ran from Warsaw, Poland, to the border southwest of Königsberg. The two armies would take the Germans in a pincer. The Russian supply chains would be ungainly because—for defense—on their side of the border there were only a few sandy tracks rather than proper macadamized roads. Adding to their supply problems, the Russians deployed large numbers of cavalry and Cossacks; every day each horse needed ten times the resources that a man required.
The First Army commander was Paul von Rennenkampf, who in the Russo-Japanese War had earned a reputation for "exceptional energy, determination, courage, and military capability." The First Army was mobilized from the Vilno Military District, and consisted of four infantry corps, five cavalry divisions and an independent cavalry brigade. The Second Army, commanded by Alexander Samsonov, was mobilized from the Warsaw Military District, and consisted of five infantry corps and four cavalry divisions. These two armies formed the Northwestern Front facing the Germans, under the command of Yakov Zhilinsky. The Southwestern Front, facing the Austro-Hungarians in Galicia, was commanded by Nikolai Iudovich Ivanov.
Communications would be a daunting challenge. The Russian supply of cable was insufficient to run telephone or telegraph connections from the rear; all they had was needed for field communications. Therefore, they relied on mobile wireless stations, which would link Zhilinskiy to his two army commanders and with all corps commanders. The Russians were aware that the Germans had broken their ciphers, but they continued to use them until war broke out. A new code was ready but they were still very short of code books. Zhilinskiy and Rennenkampf each had one; Samsonov did not. According to Prit Buttar, "Consequently, Samsonov concluded that he would have to take the risk of using uncoded radio messages."
Prelude: 17–22 August.
Rennenkampf's First Army crossed the frontier on 17 August, moving westward slowly. This was sooner than the Germans anticipated, because the Russian mobilization, including the Baltic and Warsaw districts, had begun secretly on 25 July, not with the Tsar's proclamation on 30 July.
Prittwitz attacked near Gumbinnen on 20 August, when he knew from intercepted wireless messages that Rennenkampf's infantry was resting. German I Corps commanded by Gen. Hermann von François was on their left, XVII Corps commanded by Lt. Gen. August von Mackensen in the center and I Reserve Corps led by Gen. Otto von Below on the right. A night march enabled one of François’ divisions to hit the Russian XX Corps' right flank at 04:00. Rennenkampf's men rallied to stoutly resist the attack. Their artillery was devastating until they ran out of ammunition, then the Russians retired. I Corps attacks were halted at 16:00 to rest men sapped by the torrid summer heat. François was sure they could win the next day. On his left, Mackensen's XVII Corps launched a vigorous frontal attack but the Russian infantry held firm. That afternoon the Russian heavy artillery struck back—the German infantry fled in panic, their artillery limbered up and joined the stampede. Prittwitz ordered I Corps and I Reserve Corps to break off the action and retreat also.
At noon, Prittwitz had telephoned Field Marshal Helmuth von Moltke the Younger at OHL (Oberste Heeresleitung, Supreme Headquarters) to report that all was going well; that evening he telephoned again to report disaster. His problems were compounded because an intercepted wireless message disclosed that the Russian II Army included five Corps and a cavalry division, and aerial scouts saw their columns marching across the frontier. They were opposed by a single reinforced German Corps, the XX, commanded by Lt. Gen. Friedrich von Scholtz. Their advance offered the possibility of cutting off any retreat westward while possibly encircling them between the two Russian armies. Prittwitz excitedly but inconclusively and repeatedly discussed the horrifying news with Moltke that evening on the telephone, shouting back and forth. At 20:23 Eighth Army telegraphed OHL that they would withdraw to West Prussia.
By the next morning, 21 August, Eighth Army staff realized that because Samsonov's II Army was closer to the Vistula crossings than they were, they must first relocate most of their forces to join with XX Corps to block Samsonov before they could withdraw further. Now Moltke was told that they would only retreat a short distance. François protested directly to the Kaiser about his panicking superiors. That evening Prittwitz reported that the German 1st Cavalry Division had disappeared, only to later disclose that they had repulsed the Russian cavalry, capturing several hundred. By this point, Moltke had already decided to replace both Prittwitz and his chief of staff, Alfred von Waldersee. On the morning of 22 August their replacements, Col. Gen. Paul von Hindenburg and Maj. Gen. Erich Ludendorff, were notified of their new assignments.
The Eighth Army issued orders to move to block Samsonov's Second Army. I Corps on the German left was closest to the railway, so it would take the long route by train to form up on the right side of XX Corps. The other two German corps would march the shorter distance to XX Corps' left. The First Cavalry Division and some older garrison troops would remain to screen Rennenkampf. On the afternoon of 22 August, the head of the Eighth Army field railways was informed by telegraph that new commanders were coming by special train. The telegram relieving their former commanders came later. I Corps was moving over more than 150 km (93 miles) of rail, day and night, one train every 30 minutes, with 25 minutes to unload instead of the customary hour or two.
After the battle at Gumbinnen, Rennenkampf decided to pause his First Army to take resupply and to be in good positions if the Germans attacked again. This caused them to lose contact with the German Army, which he incorrectly reported was retreating in haste to the Vistula. Both Russian armies were having serious supply problems; everything had to be carted up from the railheads because they could not use the East Prussian railway track, and many units were hampered by a lack of field bakeries, ammunition carts and the like. The Second Army also was hampered by incompetent staff work and poor communications. Poor staff work not only exacerbated supply problems but, more importantly, caused Samsonov during the fighting to lose operational control over all but the two corps in his immediate vicinity (XIII &amp; XV Corps).
On 21 August, Samsonov's Second Army crossed the border, and quickly took several border towns. The VI Corps took Ortelsburg, while I and XV Corps advanced onto Soldau and Neidenburg. On 22 August, Samsonov ordered XV Corps to advance towards Hohenstein, which they did on 23 August pushing Friedrich von Scholtz's XX Corps out of Lahna.
Battle.
Consolidation of the German Eighth Army.
The new commanders arrived at Marienburg on the afternoon of 23 August; they had met for the first time on their special train the previous night and now they rendezvoused with the Eighth Army staff. I Corps was moving by the rail line, and Ludendorff had previously counter-ordered it further east, at Deutsch-Eylau, where it could support the right of XX Corps. XVII Corps and I Reserve Corps would march towards the left of XX Corps. Ludendorff had delayed their marches for a day to rest while remaining in place should Rennenkampf attack. The German 1st Cavalry Division and some garrison troops of older men would remain as a screen just south of the eastern edge of the Königsberg defenses, facing Rennenkampf's First Army.
Hindenburg summarized his strategy, "We had not merely to win a victory over Samsonov. We had to annihilate him. Only thus could we get a free hand to deal with the