Hearing the guns on Mackensen’s front, Below proposed to swing the bulk of his corps around the south end of Lake Dadey and take the Russians in the rear. The 6th Landwehr Brigade, attached to Ostgruppe after Gumbinnen, and part of the 36th Reserve Division would screen this movement by attacking the Russian positions around Gross-Bössau. This time Below’s reservists were well served by their cavalry. The 1st Reserve Uhlans in particular stayed in close touch with Russian movements; the regiment’s messengers kept corps headquarters well informed of enemy positions. By 12:30 p.m. I Reserve Corps reached its intended line of departure without having fired a shot.
The Russians made the corps’s task even easier. The 36th Division’s halfhearted attack had convinced the 4th Division’s commander that he was facing only flank guards thrown out by Germans retreating towards the Vistula. Blagoveschensky felt justified in sending the 16th Division westward towards Allenstein around noon, in obedience to the last set of orders he had received. The 4th Division remained with one brigade facing Mackensen, the other in position south of Gross-Lautern Lake. Without a German in sight, Major-General Komarov ordered that brigade forward to support the attack that had so discomfited the 36th Division. While on the march to its new sector the brigade ran into the 36th Reserve Division and the Landwehr.
In a textbook encounter battle, the Russians held their ground well. Below’s 69th Reserve Brigade was initially shelled into immobility by the corps’s own artillery. By the time the gunners were informed of their mistake Russian machine guns, dug in to the point of invisibility, were cutting swaths through the ranks of the reservists and their older comrades of the Landwehr. Most of the latter were married men with families, correspondingly unsusceptible to heroic inspiration, advancing at their own pace when they went forward at all. In one sector the tide turned almost by accident. Two Landsturm batteries, whose middle-aged gunners and officers had served in the days before indirect fire was a part of the training manuals, closed to point-blank range to blast Russians out of a gravel pit. Even then an infantry battalion commander had to ask his men if they expected him to win the war alone before they followed the guns. With night falling, the Germans played their last cards. Generals and colonels dismounted and drew their swords; bugles sounded the charge all along the line. The 69th Reserve Brigade’s commander was wounded leading the final rush. The Russians abandoned their positions; the Germans bivouacked on the field. Here and there around their fires a few enthusiasts even raised the Leuthen Chorale, “Now thank we all our God.”
The German victory was also a Russian defeat. As the afternoon wore on it became increasingly apparent to Blagoveschensky that he faced something much more dangerous than the flank guard of a retreating enemy. He ordered the 16th Division to turn around and return to support the 4th. Since the division was advancing on a single main road, the order was easier issued than executed. Once the Russians straightened themselves out, their attention was focussed on the battle they were marching towards. Flank security and rear guards were neglected. Around the southern end of Lake Dadey the division was overtaken by the vanguard of the 1st Reserve Division. German artillery firing over open sights wreaked havoc among the unsuspecting Russians. By 4:00 p.m. the 16th Division had been driven completely out of the battle area.59
In the meantime, Mackensen’s corps had not been totally idle. Around 6:00 p.m., as the reservists were clearing Gross-Bossau, the 36th Division’s artillery opened a hurricane bombardment on the Russian positions to the division’s front. The Russians, isolated, under attack from two sides, exhausted by a stubborn, day-long defense, collapsed. When the 36th Division’s infantry advanced—cautiously behind a screen of fighting patrols—they found only abandoned positions, corpses, and stragglers anxious to give themselves up.
Total Russian casualties for the day were about 5,300 officers and men, with the Germans taking over 1,700 prisoners. But VI Corps had lost more than men. It had advanced to Bischofsburg confidently, expecting to deal with nothing more threatening than a defeated enemy retreating across its front. Its generals conducted no systematic reconnaissance. No one in a responsible position tried to verify preconceptions of the German situation. As a result one division was surprised and defeated in detail by a superior enemy while the other was moving beyond effective supporting range. Then the second division was overrun from the rear. The VI Corps was so demoralized it retreated thirty kilometers without being pursued. Blagoveschensky’s nerves collapsed even more thoroughly than his corps. Like a schoolboy caught in mischief, he waited until 2:00 a.m. on August 27 to inform his superior what had happened, using the intervening time to issue a series of confused and contradictory orders that contributed nothing to rallying his shaken troops.60
Out of this day’s battle grew something else—the story of thousands of Russians being driven into the swamps of Masuria and left to die. A part of the 4th Division actually was thrown back against Lake Gross-Bössau, and a few men did drown there. At 8:30 that night, I Reserve Corps reported that “many Russians” had been driven into the lake. Eighth Army in turn repeated the information, suitably embellished, in a later army order that François and Max Hoffmann agree was the probable basis of the legend.61
Hindsight makes the German victory over VI Corps look easier than it appeared to the men on the spot. Blagoveschensky and his subordinates may have offered opportunities; the Germans had to take advantage of them. Below and Mackensen ordered tired, footsore men, three-fourths of whom had been wearing civilian clothes a month earlier, into broken terrain against an enemy whose tenacity in defense was proverbial. Mackensen’s men in particular still showed the effects of Gumbinnen in their sudden reliance on artillery to destroy the Russians instead of merely suppressing their fire. Despite their triumph, moreover, both German commanders expected to be attacked from somewhere the next day. The II Russian Corps, its advance through the Masurian Lakes barred by Fort Boyen, had been ordered to swing north of the lakes, then turn south and establish contact with Samsonov’s army. Air reconnaissance reported prepared Russian positions south of Bischofsburg. Other airmen reported Russian troops in Gerdauen—which an intercepted order had described as being on the line of advance of Rennenkampf’s IV Corps.62
Knowledge can generate anxiety as well as power. Since Gumbinnen Mackensen’s headquarters had strong images of Rennenkampf’s energy and ability—not least because he had beaten them so badly. Current information about Russian movements was hardly comforting. Air reconnaissance still depended heavily on the skill of individual observers and the daring of individual pilots. One team might mistake a few squadrons of cavalry for an army corps; another could confuse an infantry division with a wagon train. The question facing commanders on the ground was always just how much salt to sprinkle on the information. A day earlier Mackensen’s chief of staff had grumbled to one of his subordinates that XVII Corps was in more danger than Blücher had been after Ligny a century earlier. Making worst-case assumptions, the Germans now risked being sandwiched between II and IV Corps coming south and the bulk of the 2nd Army moving north towards Allenstein.