Aisne: Despite major efforts (BEF I Corps captures 12 guns), Allies unable to enlarge much their shallow bridgeheads across the river against GERMAN TRENCHES. MOLTKE RESIGNS AS GERMAN COS; SUCCEEDED BY FALKENHAYN but not made public till November 3.
Foch’s Ninth Army unable to cross Reims-St Menehould road and lacks of artillery to capture Moronvillers heights on September 16-17.
Lorraine: Lieutenant de Lattre (12th Dragoons, 2nd Cavalry Div) kills 2 Bavarian Uhlans with his sword, but suffers lance wound west of Pont-a-Mousson (Moselle), awarded Legion of Honour, aged 25.
STAVKA orders all radio messages in cipher, but Austrian Captain Pokorny cracks it by September 19.
Poland and Galicia: Russians hold Drohobvcz oilfields and cross river San at mouth in pursuit. Lechitski’s Ninth Army retakes Sandomir on Vistula.