Italian Front – Seventh Battle of Isonzo (until September 17): Alter lengthy artillery preparation including gas shells Italian Third Army (14 divisions, 966 guns, 584 mortars) attacks at 0900 hours on 6-mile front, captures Nova Vas Hills 144, 265 and 208 (Carso) with 1,800 PoWs, later regained by Austrians (Fifth Army, 101 battalions with 409 guns).
Macedonia: Italians and French make diversionary attacks in Doiran-Vardar sector. Serbs break through at Gornichevo on Florina road and capture 32 Bulgar guns.
Battle of the Somme: British storm trenches southeast of Thiepval and 11th Div the ‘Wonderwork’. Haig and Rawlinson confer, Haig urges determined assault on Martinpuich. French I Corps captures Le Priez Farm; French XXIII and VII Corps both stalemated; 78 German counter-attacks since September 1.