Editing Battle of Tannenberg (section)

===Early phases of battle: 23–26 August===
[[Image:BattleOfTannenberg2.jpg|left|thumb|upright=1.7|Movements of 23–26 August 1914, with Germans in red and Russians in blue]]

Zhilinskiy had agreed to Samsonov's proposal to start the Second Army's advance further westward than originally planned, separating them even further from Rennenkampf's First Army. On 22 August Samsonov's forces encountered Germans all along their front and pushed them back in several places. Zhilinskiy ordered him to pursue vigorously. They already had been advancing for six days in sweltering heat without sufficient rest along primitive roads, averaging {{convert|24|km|mi|abbr=on}} a day and had outrun their supplies.<ref>Lincoln, 1986, p. 73.</ref> On 23 August they attacked the German XX Corps, which retreated to the Orlau-Frankenau line that night. The Russians followed, and on the 24th they attacked again; the now partially entrenched XX Corps temporarily stopped their advance before retreating to avoid possible encirclement. At one stage the chief of staff of the corps directed artillery fire onto his own dwelling.<ref>Showalter,  1991, p. 238</ref>

Samsonov saw a wonderful opportunity because, as far as he was aware, both of his flanks were unopposed. He ordered most of his units to the northwest, toward the Vistula, leaving only his VI Corps to continue north towards their original objective of [[Jeziorany|Seeburg]]. He did not have enough aircraft or skilled cavalry to detect the German buildup on his left. Rennenkampf mistakenly reported that two of the German Corps had sheltered in the Königsberg fortifications.<ref>Asprey, R. B.(1991) ''The German High Command at War; Hindenburg and Ludendorff conduct World War I''. London: William Morrow, p. 74.</ref>

[[File:Bundesarchiv Bild 183-R36715, Ostpreußen, deutsche Infanterie auf dem Marsch.jpg|thumb|German infantry during the Battle of Tannenberg]]
On 24 August Hindenburg, Ludendorff and Hoffmann motored along the German lines to meet Scholtz and his principal subordinates, sharing the roads with panic-stricken refugees; in the background were columns of smoke from burning villages ignited by artillery shells. They could keep control of their army because most of the local telephone operators remained at their switchboards, carefully tracking the motorcade. Along the way they drove through the village of [[Battle of Tannenberg (1410)|Tannenberg]], which reminded the two younger men of the defeat of the Teutonic Knights there by the Poles and Lithuanians in 1410; Hindenburg had been thinking about that battle since the evening before when he strolled near the ruins of the castle of the Teutonic Order. (In 1910 Slavs had commemorated their triumph on the [[Battle of Grunwald|old battlefield]].)<ref>[[Max Egremont|Egremont, Max]], (2011) ''Forgotten land : journeys among the ghosts of East Prussia''. London: Picador.{{page number|date=August 2021}}</ref>

Aided by Russian radio intercepts, a captured map of Russian positions, and information from fleeing German civilians of Rennenkampf's slow progress, Hindenburg and Ludendorff planned the encirclement of the Russian Second Army.  I Corps and XX Corps would attack from Gilgenburg towards Neidenburg, while XVII Corps and I Reserve Corps attacked the Russian right flank.  They met with Scholtz and his XX Corps staff on 24 August, and François on 25 August, where he was ordered to attack towards [[Uzdowo|Usdau]] on 26 August. François stated only part of his corps and artillery had arrived.  Ludendorf insisted the attack must go forward as planned, since more trains were expected beforehand.  François replied, "If it is so ordered, of course an attack will be made, and the troops will obviously have to fight with bayonets."{{sfn|Buttar|2016|pp=153, 159–161}}

On the way back to headquarters Hoffmann received new radio intercepts. Rennenkampf's most recent orders from Zhilinskiy were to continue due west, not turn south-westward towards Samsonov, who was instructed to continue his own drive northwest further away from Rennenkampf. Based on this information Scholtz formed a new defensive flank along the [[Drewenz]] River, while his main line strengthened their defenses. Back at headquarters Hindenburg told the staff, "Gentlemen. Our preparations are so well in hand that we can sleep soundly tonight."<ref>Showalter, 1991, p. 233.</ref>

Samsonov was concerned by the German resistance with their earlier advance, and aerial reconnaissance spotted the arrival of the German I Corps.  However, Samsonov was ordered by Zhilinski to attack northwest with Martos' XV Corps, and Klyuev's XII Corps, while I Corps protected the left flank, and VI Corps was positioned on the right at [[Bischofsburg]].{{sfn|Buttar|2016|p=161}}