STAVKA (the Russian High Command) had prepared two plans for the eventuality of war against the Central Powers, Plan G for Germany and A for Austria-Hungary. Although the mobilization of the troops stationed in Russia was somewhat delayed by G and A’s colliding railway schedules, the Russian army eventually appeared in its deployment areas faster than anticipated by the enemy.
STAVKA had established two Army Group commands for her western forces, north respectively south of the Bug – Vistula line. Army Group “Northwest” was in charge of First and Second Armies, earmarked to deploy against Germany while Army Group “Southwest” commanded Third, Fifth and Eight Armies, sharing the task of invading Galicia, the Austrian part of former Poland.
Fourth Army was the Russian version of a “swing option”: much like Joffre had originally intended for Lanrezac’s Fifth Army in France, Fourth Army could be sent into action either at the Austrian front south of Lublin, or back up, “en echelon”, First and Second Armies on their way into Germany.
The Russian post-1905 modernization program had suffered much due to arthritic Russian bureaucracy; improvements were delayed, never implemented or simply ignored; in some respects the Russian army could not meet international standards.
[First and Second Armies deployed] … nine corps to Prittwitz’ [the German C-in-C] four, and seven cavalry divisions, including two of the Imperial Guard, to his one. Rennenkampf, commanding First Army, and Samsonov, commanding Second, were moreover both veterans of the Russo-Japanese War, in which each had commanded a division, while Prittwitz had no experience of war at all. [Not true, see link above]
Their formations were very big, [Russian] divisions having sixteen instead of twelve battalions, with large masses of – admittedly often untrained – men to make up losses. Though they were weaker in artillery, particularly heavy artillery, than their German equivalents, it is untrue that they were much less well provided with shells; all armies had grossly underestimated the expenditure that modern battle would demand and, at an allowance of 700 shells per gun, the Russians were not much worse off than the French, fighting at the Marne. Moreover, the Russian munitions industry would respond to the requirements of war with remarkable success.
Nevertheless, Russia’s forces were beset by serious defects. The proportion of cavalry, so much greater than that in any other army, laid a burden of need for fodder on the transport service, itself inferior to the German, which the value given by mounted troops could not justify; forty trains were needed to supply both the four thousand men of a cavalry division and the sixteen thousand of an infantry division.
There were human defects as well. Russian regimental officers were unmonied by definition and often poorly educated; any aspiring young officer whose parents could support the cost went to the staff academy and was lost to regimental duty, without necessarily becoming thereby efficient at staff work. As Tolstoy so memorably depicts in his account of Borodino, the Russian officer corps united two classes which scarcely knew each other, a broad mass of company and battalion commanders that took orders from a narrow upper crust of aristocratic placemen. The qualities of the peasant soldier – brave, loyal and obedient – had traditionally compensated for the mistakes and omissions of his superiors but, face to face with the armies of countries from which illiteracy had disappeared, as in Russia it was far from doing, the Russian infantryman was at an increasing disadvantage. He was easily disheartened by setback, particularly in the face of superior artillery, and would surrender easily and without shame, en masse, if he felt abandoned or betrayed. The trinity of Tsar, Church, and Country still had power to evoke unthinking courage; but defeat, and drink, could rapidly rot devotion to the regiment’s colours and icons. (1)
To this litany a failed artillery policy and communication problems might be added. Russian artillery officers tended to view the main task of heavy guns in defending the chain of fortresses which secured the Russian border perimeter and were very much averse of schlepping big guns over a battlefield. Thus, Russian armies were chiefly equipped with small and medium calibre guns, of lesser firepower and diminished range. As in the naval gun race, lighter guns became the victims of the enemy’s heavier ones; for lack of range unable to return the fire. Radio communications suffered from a lack of trained cipher clerks, which forced the radiomen to transmit many message en clair, especially in the heat of battle.
In the event of August 1914, Fourth Army marched south, to the Austrian border, and Army Group Northwest dispatched First and Second Armies to East Prussia. The plan envisioned a two-pronged manœuvre of enveloping 8th Army. STAVKA directed Rennenkampf to attack north of the lakes and the Angerapp River east of Königsberg and to proceed along the Baltic Sea Coast in westerly direction. Samsonov was ordered to invade from the south-east – from the direction of Warsaw - and to march in north-westerly direction until he would meet Rennenkampf, coming from the other direction, somewhere on the Vistula, perhaps in the vicinity of Marienwerder or Marienburg. The defenders would be surrounded and once the Vistula was gained, the way into West Prussia and Silesia lay open.
The plan had two weaknesses: it was obvious, as a tarantula on the cheesecake, and it depended upon close coöperation and communication of the two armies, conduct neither Rennenkampf nor Samsonov were renowned for. The German General Staff had actually based pre-war games upon the premise of such a two-pronged attack and had established that the correct counter-strategy was to delay one prong while attacking the other. Such a strategy necessitated rapid troop movements between the two sides of the Lakeland, the north-eastern part around Insterburg and Gumbinnen, and the south-western side from Allenstein in the centre of the province to Thorn on the Vistula. A direct railway was built traversing the Lakeland for this exact purpose, running along a line Gumbinnen – Insterburg – Allenstein – Osterode – Deutsch-Eylau – Thorn.
The map below shows the early stage of the East Prussian campaign. The Russians appeared three weeks earlier than anticipated, Rennenkampf’s vanguard crossing the border and reconnoitring in westerly direction on August 15. Two days later, his III, IV and XX Corps marched on Gumbinnen, eighty miles east of Königsberg. They were screened by his 1st Cavalry Division on their southern flank and the Guards Cavalry Corps on the northern one. Their counting on strategic surprise, however, was nullified as early as August 9 on account of the German 2nd Aircraft Observer Battalion and the services of two dirigibles stationed at Königsberg and Posen. They informed Prittwitz of the Russian presence, but what worked for the Germans failed, inexplicably, for the Russians: their cavalry could not find any trace of the enemy, and Rennenkampf’s aerial reconnaissance unit, consisting of a fleet of 244 aircraft, mysteriously failed to spot a single German unit.
The most important information for Prittwitz was that Second Army seemed to be late. The German staff began to believe that they might have a shot at Rennenkampf first and Samsonov later.
Geography was to disrupt the smooth onset of the Russian combined offensive in space. Less excusably, timidity and incompetence were to disjoint it in time. In short, the Russians repeated the mistake, so often made before by armies apparently enjoying an incontestable superiority in numbers, the mistake made by the Spartans at Leuctra, by Darius at Gaugamela, by Hooker at Chancellorsville, of exposing themselves to defeat in detail: that is, of allowing a weaker enemy to concentrate at first against one part of the army, then against the other, and so beat both.
The way in which geography worked to favour the Germans’ detailed achievement is the more easily explained. Though eastern East Prussia does indeed offer a relatively level path of advance to an invader from Russia, the chain of lakes that feeds the River Angerapp also poses a significant barrier. There are ways through, particularly at Lötzen, but that place was fortified in 1914.
As a result, a water barrier nearly fifty miles long from north to south confronted the inner wings of First and Second Army, so tending to drive them apart. Strategically, the easier option was to pass north and south of the Angerapp position rather than to force it frontally, and that was what the commander of the North-Western Front, General Yakov Zhilinsky, decided to direct Rennenkampf and Samsonov to do.
He was aware of the opportunity such a separation offered to the Germans and accordingly took care to provide for the protection of his two armies’ flanks. However, the measures taken enlargened the danger, since he allowed Rennenkampf to strengthen his flank on the Baltic coast, which was not at risk, and Samsonov to detach troops to protect his connection with Warsaw, equally not threatened, while arranging for one corps of Second Army [II Corps] to stand immobile in the gap separating it from First. The result of these dispositions was a diversion of effort which left both armies considerably weakened to undertake the main task. Having commenced the deployment with a superiority of nineteen divisions against nine, Rennenkampf and Samsonov actually marched to the attack with only sixteen between them.
Worse, critically worse, the two armies arrived at their start lines five days apart in time. First Army crossed the East Prussian frontier on 15 August, a very creditable achievement given that the French and Germans were then still completing their concentration in the west, but Second not until 20 August. As the two were separated in space by fifty miles of Lakeland, three days in marching time, neither would be able to come rapidly to the other’s assistance if it ran into trouble which, unbeknownst either to Rennenkampf or Samsonov, was the way they were heading. (2)
The aviators’ intelligence initially paid off for Prittwitz. When Rennenkampf began offensive operations on August 17, Prittwitz knew that Samsonov was late and thus could momentarily afford to keep most of 8th Army in the north-east. A Russian probe which showed up at the small town of Stallupoenen, ten miles east of Gumbinnen, was quickly checked, but when Prittwitz ordered a counter-attack of General Herrmann von François’ I Corps on August 20, the Russians had already prepared an entrenched position near Gumbinnen. I Corps was, as was the whole 8th Army, composed of East Prussian men defending their homeland, and their aggressiveness in assaulting a fortified Russian position cost them dearly.
By mid-afternoon, I Corps had come to a halt. Its neighbouring corps, XVII, commanded by the famous Life Guard Hussar, von Mackensen, who was encouraged by early reports of its success, was meanwhile attacking north-eastwards into the Russians’ flank.
It did so without reconnaissance which would have revealed that, on its front as on that of von François, the Russians were entrenched. From their positions they poured a devastating fire into the advancing German infantry who, when also bombarded in error by their own artillery, broke and ran to the rear. By late afternoon the situation on the front of XVII Corps was even worse than that on the front of I Corps and the Battle of Gumbinnen was threatening to turn from a tactical reverse to a strategic catastrophe.
To the right of XVII Corps, I Reserve, under von Bülow, counter-attacked to protect Mackensen’s flank against a Russian advance. At Eight Army headquarters, however, even the news of that success could not stay the onset of panic. There Prittwitz was yielding to the belief that East Prussia must be abandoned and the whole of his army retreat beyond the Vistula. (3)
The big red arrow on the map above shows the intended retirement to the west, beyond the Vistula, that Prittwitz thought unavoidable. The bold blue arrows in squares DE 3 – 4 symbolize Rennenkampf’s III, IV and XX Corps, moving westward, into the direction of the fortified zone of Königsberg. At its southern flank, First Army is protected by 1st Cavalry Division and in the north by the Guard Cavalry Corps. Squares BCD 1 – 2 show Second Army, composed of I, XXIII, XV, XIII and VI Corps, plus 15th, 6th and 4th Cavalry Divisions. Samsonov’s II Corps is located in the geographical middle of the Lakeland, square DE 2, in the act of being transferred to Rennenkampf on August 21. It is on the way north-west, to join First Army at Angerburg.
At OHL [Supreme Command] Moltke balked at the very thought of withdrawing 8th Army behind the Vistula. But for the margins of the operational plan being too narrow, Moltke had no troops available for an immediate reinforcement. To make the situation worse, the men of 8th Army had their roots and families in East Prussia; an order to retreat might cause a revolt. Moltke decided that a new broom was needed on the Eastern front. Two brooms, actually.
Moltke decided first that a director of operations of the first quality must be sent instantly to the east to take charge. He chose Ludendorff, who had twice so brilliantly resolved crises in Belgium. He next determined to dispose of Prittwitz altogether, judging his declared intention to retire behind the Vistula, even if subsequently reconsidered, to be evidence of broken will.
In his place he promoted Paul von Beneckendorff and Hindenburg, a retired officer noted for his steadiness of character if not brilliance of mind. As a lieutenant in the 3rd Foot Guards, Hindenburg had been wounded at Königgrätz in 1866 and fought in the Franco-Prussian War. He claimed kinsmen among the Teutonic Knights who had won East Prussia from the heathen in the northern crusades, had served on the Great General Staff and eventually commanded a corps.
He had left the army in 1911, aged sixty-four, but applied for reappointment at the war’s outbreak. When the call from Moltke came, he had been out of service so long that he was obliged to report for duty in the old blue uniform that had preceded the issue of field-grey. He and Ludendorff, unalike as they were, the one a backwoods worthy, the other a bourgeois technocrat, were to unite from the start in what Hindenburg himself called “a happy marriage.” Their qualities, natural authority in Hindenburg, ruthless intellect in Ludendorff, complemented each other’s perfectly and were to make them one of the most effective military partnerships in history. (4)
On August 23, Hindenburg and Ludendorff arrived at Rastenburg whither the HQ of 8th Army had been moved, and summoned the staff for a conference the very next day. The discussion began with an analysis of the situation by General Scholtz, commander of XX Corps which was, at the moment, the sole German unit opposing the slowly advancing Samsonov in the south. Strategically, the newcomers in command were much aided by a resolution Prittwitz had enacted
just before he was relieved of duty. During his years at the Staff Academy, Prittwitz had participated in the aforementioned war games and hence was familiar with the East Prussian counter-strategy, which called to defeat the Russians “in detail”. Prittwitz had decided that, after the tie at Gumbinnen, as he saw it, Rennenkampf could be counted as checked, and that First Army would typically need a few days to regroup and redeploy. If he acted fast, he might beat Samsonov in the south before Rennenkampf, in the east, resumed the offensive. Ably assisted by his Chief of Staff, Colonel Max Hoffmann, he ordered von François’s I Corps from Königsberg whither it had retired, and von Mackensen’s XVII Corps, at the moment south-west of Gumbinnen, to entrain southward to meet Samsonov.
These movements are indicated on the map below by the thin dashed lines and bold red arrows, showing the early stages of the German movements. I Corps retired to Königsberg in order to board the coastal railway line while XVII and I Reserve traversed first westward, then south-west, into the direction of Allenstein. Scholtz’s II Corps was already in the vicinity, around the small towns of Hohenstein and Tannenberg.
Thus, Hindenburg and Ludendorff did not have to design a new plan, whose development might have cost precious time but were able to adopt Prittwitz’s strategy, which they pursued at best speed. To their aid came a few monumental errors in the Russian dispositions, chiefly by Rennenkampf. When First Army’s forward reconnaissance units, after the four days of the Battle of Gumbinnen, reported that the presence of German troops facing them was thinning out, Rennenkampf assumed that 8th Army had retreated to the fortified zone of Königsberg. Such a move might be reasonable, at some level, since it would compel First Army to a lengthy siege, which might give the Germans time enough to send reinforcements from the Western Front. Thus, Rennenkampf stopped the pursuit of I and XVII Corps, consolidated his territorial gains, and initiated preparations for the upcoming siege.
He reported his decision to STAVKA and asked for assistance with the investment of Königsberg, for which his troops, lacking heavy artillery, were ill prepared. But since the delay meant that he was, for the time being, incapable of keeping touch with the rest of the German army, he proposed to Zhilinsky to send Samsonov in the direction of the Vistula, i.e. north-west. Once First Army had reduced Königsberg, the planned envelopment of 8th Army could be reactivated. Army Group Northwest followed Rennenkampf’s suggestion and Samsonov was ordered to proceed in north-western direction, to the Vistula, but away from First Army.
Rennenkampf’s proposition was risky in itself – what if the siege failed? But what transpired in the event was worse. On the morning of August 25, First Army’s radio traffic with STAVKA and Army Group Northwest, which included the siege plan, was intercepted and deciphered by Ludendorff’s radio monitors. Moreover, the messages yielded the priceless information that First Army would halt and thus be unable to support Second Army in case it headed into trouble.
Rennenkampf’s decision to halt allowed Hindenburg and Ludendorff to concentrate against Second Army. They could afford to leave Königsberg essentially unprotected except for its entrenched garrison and a weak screen of 1st Cavalry Division [see map above, the red dots, C 3 – 4, west of Rennenkampf]. Now the railways came into play. The existence of two lines allowed 8th Army to route parts of XVII and I Reserve Corps southward, via the Insterburg-Allenstein line traversing East Prussia, and to convey I Corps by the coastal railway to Elbing, and then route them via Marienburg and Deutsch-Eylau to Seeben, into a position opposite the left flank of Samsonov’s I Corps which stood between Soldau and Usdau. Ludendorff even ordered the small Vistula garrison from Thorn to meet François’s I Corps near Lautenburg [Map above, square B 1]. By August 26, XVII Corps stood at Bischofstein [Map above, C 3], and I Reserve between Allenstein and Seeburg [Map above, C 2 – 3], opposing Samsonov’s northernmost unit, VI Corps at Bartelsdorf. The main body of Second Army still stood south of Allenstein [XIII, XV and XXIII Corps, Map above, BC 1 – 2].
The tactical situation on the map above depicts the advantage the Germans earned by the flexibility of their troop movements, which, in addition, almost completely evaded Russian detection. There were hardly any German troops left in the north-east, vis-a-vis Rennenkampf – except for the very light screen of 1st Cavalry – and the Russian II Corps, now detached to First Army’s southern flank, lingers in a completely uncontested area. Except for her cavalry, First Army remained almost stationary; by August 26 it had moved barely ten miles west – cautiously – through empty land. Second Army was still moving north-west but was spreading all over the Lakeland, from Zielun, 15th Cavalry in the south-west, to Sensburg, 4th Cavalry, in the north-east. This was when Hindenburg ...
… was passed the transcript of a complete Russian First Army order for an advance to the siege of Königsberg which revealed that it would halt some distance from the city on 26 August, well short of any position from which it could come to Second Army’s assistance in the battle he planned to unleash.
Furnished with this assurance, he met von François, whose corps was just beginning to arrive at Samsonov’s flank, in confident mood. Distance was working for him, the distance separating Samsonov and Rennenkampf’s armies, and so now too was time, the self-imposed delay in Rennenkampf’s advance which, had it been pressed, would have put the First Army well behind the Lakeland zone in positions from which it could have marched south to Samsonov’s assistance. (5)
Hindenburg and Ludendorff’s plan were successive attacks into Second Army’s right flank, that is, to attack from Allenstein in south-western direction. François’s I Corps was to begin the offensive on August 25.
Then François, whose stubborn aggressiveness could take a wilfully uncooperative form, interrupted the smooth unrolling of a plan that should have brought his I Corps, XVII and XX successively into action against Samsonov’s flanks. Claiming that he was awaiting the arrival of his artillery by train, he was slow off the mark to attack on 25 August, and slow again the next day.
Ludendorff arrived to energize the offensive, with characteristic effect, but François’s hesitation had meanwhile had a desirable if unintended result. Unopposed in force to his front, Samsonov had thrust his centre forward, towards the Vistula against which he hoped to pin the Germans, thus exposing lengthening flanks both to François, now to his south, and to Mackensen and Scholtz, who were marching XVII and XX Corps down from the north. On 27 August François rediscovered his bite, and pushed his men on. Samsonov, disregarding the danger to his rear, pressed on as well. On 28 August his leading troops savaged a miscellaneous collection of German troops they found in their path and broke through almost to open country, with the Vistula beyond.
Ludendorff, seized by a fit of his nerves his stolid appearance belied, ordered François to detach a division to the broken units’ assistance. François, creatively uncooperative on this occasion, did not obey but drove every battalion he had eastward at best speed. With the weight of Samsonov’s army moving westward by different routes, there was little to oppose them. On the morning of 29 August, his leading infantry reached Willenberg, just inside East Prussia from Russian territory, and met German troops coming the other way [see map below]. They belonged to Mackensen’s XVII Corps, veterans of the fighting south of the Masurian Lakes, who had been attacking southward since the previous day. Contact between the claws of the two pincers – the units were the 151st Ermland Infantry of I Corps and the 5th Blucher Hussars of XVII – announced that Samsonov was surrounded. (6)
The map above portrays the situation on August 30. I Corps had begun its move at Seeben and marched east via Niedenburg, to Willenburg. Since Samsonov was marching in the opposite direction, north-west, none of his units encountered I Corps, and Second Army remained oblivious of the Germans’ presence in their rear. After I and XVII Corps had met at Willenburg, Scholtz’s XX Corps closed the trap on the western side. Except for VI Corps which escaped by retiring in south-eastern direction over the Russian border, the whole of Second Army was caught in a huge pocket east of the towns of Hohenstein and Tannenberg.
The bag amounted to approximately 50,000 Russian casualties and 92,000 prisoners, compared with losses of about 30,000 killed, wounded or missed on the German side. These numbers made the Battle of Tannenberg, as it was named according to Hindenburg’s wishes, a most particular event compared to the battles on the Western front which frequently caused wholesale destruction but so far had rarely yielded significant numbers of prisoners. For the moment, the danger to East Prussia and Silesia was averted, and Hindenburg and Ludendorff hailed as the saviours of the nation.
Rennenkampf, however, proved a tougher customer than Samsonov. When the Germans, now reinforced by the arrival of IX and the Guard Reserve Corps from France, attempted to repeat the encircling manœuvre against First Army, Rennenkampf managed to evade the German pincers adroitly in what was called the First Battle of the Masurian Lakes. On 13 September he was safely back in Russian territory, regrouped, and, reinforced by a new Russian army, the Tenth, conducted a counteroffensive which succeeded in re-establishing a Russian line near the Angerapp River, which was held until February 1915.
      Keegan, John, The First World War, Vintage Books 2000, ISBN 0−375−40052−4361, pp. 140 – 41, 142 – 44, 145, 145 – 46, 148, 148 – 49
(© John Vincent Palatine 2015/19)