Tuesday, August 18
The Russians Take Stock
Russian troops march along a railroad
After the defeat at Stalluponen on 17 August the Russians held their positions to consolidate, thinking that they had encountered the main force of the German 8th Army rather than merely elements of I Corps. In response, General von Rennenkampf concluded that if the Germans were in strength in that location, then a gap may exist further north between the 8th Army and the fortress of Konigsberg. He ordered his men to shift northward toward the area of the gap, leaving the Germans to execute their withdrawal back to the Angerapp without interference.
Meanwhile, to the south, German aerial reconnaissance had noted that the Russians force massing along the Narew in Poland had begun to move out, marching to the west. This was leading to a widening gap between the Russian 1st and 2nd Armies, and providing early warning of a great pincer movement to envelop the entire 8th Army.
East Prussia - August 18, 1914
Fortress City of Konigsberg
Nordenberg - 8th Army Headquarters
I Corps Positions
Landwehr units
I Reserve Corps Position
Fort Boyen - 3rd Reserve Division
XX Corps Positions
Russian 1st Army - Movements today to flank northward between I Corps and Konigsberg
Russian 2nd Army - Today begins to march eastward