Western Front
Third Battle of Ypres: Legendary French ace Georges Guynemer (54 victories) missing over Poelcapelle aged 22, first revealed in London (September 27) on a day Germans claim 6 Allied single-seaters.
French fighter ace Georges Guynemer (second from right) in front of his Morane-Saulnier Type L fighter:
https://i0.wp.com/ww2-weapons.com/w...-MS-L.jpg?ssl=1
British bomb south of Lille and Roulers region heavily.
British seaplanes bomb Zeebrugge mole and air sheds.
Eastern Front
Romania: Battle of Ciresoaia: (until September 12): Russo-Rumanian attack fails, last major fighting in sector.
Southern Front
Eleventh Battle of the Isonzo: After shelling of record intensity Italian 11th Division captures Mt San Gabriele with 2,000 PoWs but Austrian fire forces it 100 feet below summit; Lieutenant-Colonel Sauer of Austrian 14th Regiment ‘Who could fully describe this San Gabriele, this sort of Moloch which swallows up a regiment every three or four days …’.
Austro-Hungarian counter-attacks on Bainsizza Plateau and north-east of Gorizia heavily repulsed.
Naval and Overseas Operations
Eastern Atlantic:
U-49 (Hartmann) rammed and sunk by SS British Transport west of Biscay, having claimed 38 ships worth 86,433t.
Political, etc
Russia: Despite being labeled a traitor by the Russian government, General Kornilov & his troops are 33 miles from Petrograd & closing.
Kornilov issues final Order No 900 and appeal to the people.
United Kingdom: First party of repatriated British prisoners reaches England from Switzerland (see May 13th, 1916).
Italy: British War Minister Lord Derby visits Cadorna at Udine, promises 160 British heavy guns (200 Anglo-French guns sent on September 18).