This is the order of battle for both the Russian and German armies at the Battle of Tannenberg, August 17 to September 2, 1914.
Russian Northwestern Front
General Yakov Zhilinsky, Front Commander (not present)
Maj. Gen. Sir Alfred Knox, British Military Attache (attached to 2nd Army)
First Army
General Paul von Rennenkampf, Commander
Lt. Gen. Gavriil Mileant, Chief of Staff
II Corps (transferred from the Second Army, 22 August) – General Sergei Scheidemann
26th Infantry Division
43rd Infantry Division
III Corps – General Nikolai Epanchin
25th Infantry Division
27th Infantry Division
IV Corps – General
30th Infantry Division
40th Infantry Division
XX Corps – General Vladimir Vasilyevich Smirnov
28th Infantry Division
29th Infantry Division
Unattached
56th Infantry Division
221st Roslav Infantry Regiment
222nd Krasnan Infantry Regiment
223rd Odoev Infantry Regiment
224th Yukhnov Infantry Regiment
73rd Artillery (Reserve) Brigade
5th Rifle Brigade
1st Guard Cavalry Division – Lt. Gen. 1st Brigade Chevalier Guard Regiment Guard Cavalry Regiment 2nd Brigade Guard Cuirassier Regiment of the Emperor Guard Cuirassier Regiment of Empress Marie
2nd Guard Cavalry Division – Lt. Gen. Georgy Ottonovich Rauch
1st Brigade
Guard Horse Grenadier Regiment
Guard Ulan Regiment of the Empress
2nd Brigade
Guard Dragoon Regiment
Guard Hussar Regiment of the Emperor
1st Cavalry Division– Lt. Gen. Vasily Gurko
2nd Cavalry Division – Lt. Gen. Huseyn Khan Nakhchivanski
3rd Cavalry Division – Lt. Gen.