Battle of Tannenberg
The Battle of Tannenberg, also known as the Second Battle of Tannenberg, was fought between Russia and Germany between 26 and 30 August 1914, the first month of World War I. The battle resulted in the encirclement and the almost complete destruction of the Russian 2nd Army by the German 8th Army and the suicide of its commanding general, Alexander Samsonov. A series of follow-up battles led to the ousting of the Russian 1st Army from East Prussia.
The outcome brought considerable prestige to the German army commander, General Paul von Hindenburg, and his rising staff-officer Erich Ludendorff. Although the battle actually took place near Allenstein, 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.
The East Prussian campaign is particularly notable for fast rail movements by the German 8th Army, enabling them to concentrate against each of the two Russian armies in turn, first delaying the 1st Army and then destroying the 2nd before once again turning on the 1st 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. After the battles of Stallupönen and Gumbinnen, the German army was forced to retreat by the 1st Army. Yakov Zhilinsky, the leader of the Russian Northwestern Front, of which the 2nd and 1st Armies were a part, based on a report from the 1st Army, drew a non-existent picture for Samsonov about the German withdrawal, partly to the Vistula, partly to Königsberg, without any knowledge of the order in which they were withdrawing or where they were located. Samsonov's Russians, in turn, uncertain of the German army's exact location, acted as if counting "on a miracle" during their offensive.
In the course of the Russian offensive into East Prussia, there was no agreement between Samsonov and Zhilinsky, concerning the direction in which the 2nd Army would engage in battle; Samsonov moved to the northwest and intended to continue, but Zhilinsky intended to strike north. This disorganized leadership contributed to the disastrous defeat as well; it was globally present in the senior command staff. In the end of disputes about the army's movement, Zhilinsky chose to find the golden mean, he gave in to Samsonov, with the fact that the latter agreed to detach only the 6th Army Corps to Bischofsburg, in the direction that Zhilinsky intended. This corps escaped encirclement, though it was also defeated separately. Zhilinsky did not give Samsonov any specific orders at Tannenberg; the latter actually acted independently and this already put pressure on the psyche of Samsonov. In addition to the previous, the Imperial Russian Army began the war without a sufficiently trained officer corps, with a small reserve for new formations and for the training of conscripts, with a sharp, compared to the Germans, shortage of artillery, very poorly supplied with all technical means and ammunition, having in its rear a country and its military administration unprepared for waging a major war and an industry completely unprepared for the transition to work for military needs. Moreover, the Russians also had problems supplying their armies due to bad local infrastructure and with the fact that they deployed very significant horsepower, which required larger food supplies that were already critical.
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 8th 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 in charge of this attack and had pledged to put 800,000 men on the front by the 15th day of mobilization. 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 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. 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. 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 1st Army would use the line that ran from Vilnius, Lithuania, to the border southeast of Königsberg. The 2nd 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 becausefor defenseon 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 1st 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 1st Army was mobilized from the Vilno Military District, and consisted of four infantry corps, five cavalry divisions and an independent cavalry brigade. The 2nd Army, commanded by Alexander Vasilyevich 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 Zhilinsky 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. Zhilinsky 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 1st 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 20th Army 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 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 2nd Army included five Corps and a cavalry division, and aerial scouts saw their columns marching across the frontier. They were opposed by the reinforced German XX Corps, 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, 8th Army telegraphed OHL that they would withdraw to West Prussia.
File:Paul von Hindenburg von Nicola Perscheid.jpg|thumb|upright=0.9|Generalfeldmarschall Paul von Hindenburg|alt= An old photograph of a man with a moustache in military uniform.
By the next morning, 21 August, 8th Army staff realized that because Samsonov's 2nd 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 8th Army issued orders to move to block Samsonov's 2nd 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 1st Cavalry Division and some older garrison troops would remain to screen Rennenkampf. On the afternoon of 22 August, the head of the 8th 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 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 1st 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 2nd 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.
On 21 August, Samsonov's 2nd 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.