The explanation was not long in coming. When the 3rd Brigade had deployed that morning its commander kept the battalion in question in brigade reserve. Its commander had been marked before the war as having “bad nerves,” which might mean anything from an unfair efficiency report through a slightly overactive imagination to acute dipsomania. Brigadier-General Mengelbier was neither the first nor the last commander to cope with a weak link by putting him in a position where he could be directly supervised. This time everything went wrong. Mengelbier had proposed to establish his command post with the battalion, but was unable to find the unit in the fog. The anxious major for his part lost touch with his regiment, his brigade, and his division. The few reports he received from stragglers and fugitives were of Russians everywhere. In a kind of homing instinct he marched his men back to Montowo, picking up most of two machine-gun companies and part of a cavalry regiment along the way. By the time he reached the town he had apparently convinced himself of the truth of the story of disaster that was his sole protection against disgrace unthinkable to a German regular officer. Then the telephone caught up with him.27
If confusion ended as farce in the south, it threatened to become tragedy in the north. Below’s and Mackensen’s corps had spent an uneasy night after their victory on the 26th. Instead of merely bivouacking in the field they were ordered to dig in—a task easier outlined on a staff map than executed in pitch darkness. Trenches and rifle pits wound up facing every point of the compass. Guns painfully positioned at midnight were revealed at dawn to be targeted on their own rear areas. Company officers were not particularly sorry when orders came to abandon the area before their superiors had time to inspect the scene. The men were even more pleased to find the Russians running faster than the Germans were chasing them. Dismounted cavalry scattered the few stragglers remaining in Bischofsburg. Airmen reported a corps’s worth of Russians on the road south. Civilians described the enemy’s flight in lurid terms.
In XVII Corps headquarters, the previous day’s misgivings gave way to a euphoria sanctioned by higher authority around 12:30 p.m., when the army order to march south finally reached Mackensen. Below, arguing that his men were too fatigued to get very far, had asked Mackensen to assume full responsibility for the pursuit.28 By their own accounts at least, the regimental officers were overwhelmed with volunteers. The corps’s two cavalry regiments, the 5th Hussars and the 4th Mounted Rifles, began the chase, followed by machine guns, artillery, and infantry riding trucks borrowed from the supply columns or bicycles commandeered from civilians. When the cavalry, its horses blown, bivouacked for the night, the infantry kept moving. At 2:15 a.m. on August 28 an improvised flying column consisting of a battalion of the 175th Infantry supported by the regimental machine gun company, a battery of field guns, and two troops of cavalry reached Passenheim. The village had been ransacked by the retreating Russians, who left behind an entire ammunition column and a war chest containing 200,000 rubles.29
Thus far, so good. But at 9:00 p.m. on August 27, Ludendorff’s evening was disturbed by a phone call from I Reserve Corps. One of its cavalry patrols had just arrived with information. Strong Russian forces, estimated as at least a division, had in fact occupied Allenstein. When the troopers left at 4:00 p.m. to report, Russians were still marching in. Apparently the enemy in that sector was much stronger than anyone had thought. Possibly, moreover, XIII Corps, instead of turning against Scholtz as expected, was trying to extend north and east to join Rennenkampf’s II Corps, which according to the best German information had reached Rastenburg by 11:00 a.m. on the 27th. If this happened the rearward communications of XVII Corps and I Reserve Corps would be well and truly severed. Below therefore proposed that the full strength of both his and Mackensen’s corps be turned against Allenstein the next morning in order to drive the Russians there south onto the guns of Scholtz, Morgen, and Goltz.
Army command approved the change in plans. The I Reserve Corps and elements of XVII Corps were ordered to attack Allenstein the next day. The two corps must strive to mount a joint attack by noon, but I Reserve Corps was definitely to be in action at that time. To ensure that contingency, Below was to move out without waiting for Mackensen. August 28, declared Ludendorff, must be the day of decision.30
Mackensen’s headquarters still had not established a direct telephone link with army headquarters in Löbau. With Allenstein in Russian hands, even a fast car would have to make elaborate detours over questionable roads to maintain contact. The army staff therefore expected Below to pass the revised orders along to Mackensen. He did not—at least not in the form intended. Instead Colonel Posadowsky, chief of staff of I Reserve Corps, drove to Mackensen’s headquarters in person and informed him that the entire XVII Corps, including the detachment at Passenheim, was to move on Allenstein, extending only security detachments south towards Jedwabno and Ortelsburg.
After the war Mackensen wrote that this turn against Allenstein was so much opposed to his view of the situation that at first he hesitated to execute the operation. Army headquarters only noted that Below’s headquarters “misunderstood” the new orders.31 The confusion is not hard to understand. The general army order issued at 10:00 p.m. said that “elements” of XVII Corps would cooperate with I Reserve Corps around Allenstein. “In addition,” the former corps was to drive south “in the direction of Willenburg.”32 However, the specific orders sent to I Reserve Corps stated that on August 28 XVII Corps was to advance on Ortelsburg while attacking Allenstein. The two towns were in opposite directions from the corps’s current position. The missions were not exactly mutually contradictory. But in the face of an enemy whose strength and positions remained uncertain, pursuing them simultaneously might put Mackensen’s corps in the position of the proverbial chameleon on a plaid shirt. Instead of striking a concentrated blow, it risked the fate of being too weak everywhere, and too tired from overmarching, to accomplish anything.
In his study of the Tannenberg campaign, N. N. Golovine argues that the German orders were intended to provide a barrier against Rennenkampf, rather than to expedite the annihilation of Samsonov. According to his interpretation, Ludendorff intended Ostgruppe to remain more or less in position while XX Corps and I Corps pursued the 2nd Army and drive it south. These latter corps would then disploy on the right flank of Ostgruppe, with the Goltz Division and the 3rd Reserve Division in reserve, to face Rennenkampf should he move south. Golovine asserts that the orders to march on Allenstein did not reach Mackensen directly because “some calmer person” at army headquarters intervened to prevent this. Posadowsky was sent to XVII Corps Headquarters by mistake, because Below did not understand either the situation or his orders.33
The thesis, though provocative, does not appear tenable in light of the German records. Fatigue played a significant role in the mix-up. Mackensen was sixty-five, Below fifty-seven. Their principal staff officers were men in late middle age. While they were collectively fit enough none was as yet accustomed to, or indeed fully aware of, the constant stress of campaigning under conditions of modern war. These were not the circumstances of 1916 or 1917, when staffs spent months at a time in the same comfortable surroundings. The corps of Ostgruppe had been on the move since the start of the campaign. Questions of interpretation that seem obvious in a scholar’s study or the academic precincts of a war college can loom much larger late at night in a field headquarters to men whose lifetime routines of eating, sleeping, and moving their bowels have been rudely and systematically shattered.