Western Front
Battle of the Somme: Battle of Thiepval Ridge begins (until 28th). British with 13 Tank Mk I capture Thiepval (18th Division German soldier writes ‘… it was absolutely crushing’), 56th Division with 2 tanks and 2 French regiments captures Combles, and Gird Trench; first air-tank co-operation with 21st Division at Guedecourt (400 PoWs) captures 500 yds of trench for 5 casualties. This is the first major attack by the British Reserve Army, later renamed the Fifth Army.
Foch redirects main French attack due north on Sailly – Sallisel (V Corps covers their flank) but launched at 1600 hours achieves little (vainly repeated on September 27). Commander Fayolle tries to resign due to this failure. British cavalry pursues Germans. “Quantity” of stores and “many” (see above: “many” is 400) prisoners taken.
Soldier of the British Royal Fusiliers wearing a captured German helmet near Thiepval:
http://imgur.com/PpyOHlk* © IWM (Q 1331)
View of Morval village at the Somme after its capture by the Allied forces:
http://imgur.com/WjNt07b*© IWM (Q 4299)
Eastern Front
Vulkan Pass regained by Romanians.
Battle of Hermannstadt (until September 29): Falkenhayn’s Ninth Army attacks in fine weather towards Rotenturm Pass (11,555 ft) which German Alpenkorps crosses, Hermannstadt retaken (September 29); 3,000 Rumanian PoWs in First Army defeat.
Southern Front
Athens: Greek ships have joined the Allied fleet under Admiral du Fournet, the French Commander-in-Chief.
Asiatic and Egyptian Theaters
Armenia: First snow falls. Turks evacuate Mus, their Second Army losses 30,000 (since August 2) reducing it to 60,000 soldiers. Russian losses 50,000 since June including in Persia. Early winter quarters for both sides.
Naval and Overseas Operations
East Africa: General Sir C. Crewe occupies Igalulu, east of Tabora.