Western Front
Battle of the Somme: Great (only “Great” compared to earlie disasterous British advances) British advance (third phase) on the Somme, a six-mile front to depth of 2 or 3,000 yards. Flers, Martinpuich, Courcelette and whole of High Wood taken.
New heavy armoured vehicles (Tanks) used for first time, north of Pozieres to east of Guillemont:
Battle of Flers-Courcelette begins (see 22nd). From 0620 hours, after 40-minutes shelling, 14 divisions (2 Canandian and 1 NZ) and 32 of 49
FIRST TANK MK I‘s IN ACTION (see July 28th, 1917). The British Mark 1 tank is a huge shock to the German defenders. The first official tank photograph:
http://imgur.com/GJWd2Z6 © IWM (Q 2488)
Four Mark I tanks being refueled at Chimpanzee Valley:
http://imgur.com/GQBIOkt* © IWM (Q 5576). Despite the shock, not everything goes well with the tanks: 5 ditched, 9 break down, 10 hit.
Aeroplane co-operation with tanks instituted by the British Flying Corps:
During the Battle of Fleurs-Courcelette, No.7 and No.34 Squadrons, Royal Flying Corps, support the British Army's first tank attack. Royal Flying Corps helps engage 85 German batteries (29 silenced) and drops 8t bombs on 15 targets; claims 15 German aircraft, loses 14 aircrew and 6 aircraft. Second Lieutenant Ball destroys or forces down 10 German aircraft until September 28.
French capture trenches south of Rancourt, and system of trenches north of Le Priez Farm, south of Somme, east of Deniecourt, etc. the french also repulse frequent counter-attacks. Micheler regrets lack of reserves prevents follow-up operations.
146 extra heavy guns sent to German First and Second Armies at the Somme and 144 worn*out guns replaced (until October 8).
Hindenburg issues his first formal operation order: ‘The main task of the Armies is now to hold fast all positions on the Western, Eastern, Italian and Macedonian fronts and to employ all other available forces against Rumania’.
Situation map at the Somme, with the shaded regions denoting Allied advances:
http://imgur.com/18P5xv7
(note the lack of scale on the map, making the gain look a whole lot bigger than they actually were).
Eastern Front
Brusilov Offensive, Galicia: General Kaledin with Eighth Army HQ transferred south to command, troops between Lechitski and Sakharov, Gourko’s Special Army takes over Brusilov’s northern flank.
Southern Front
Seventh Battle of Isonzo: Lower Isonzo: Italians take San Grado, strong entrenchments towards Loquizza, and claim over 1,800 prisoners.
Monte Rosa Alpini Batallion captures Mt Cauriol (7,605 ft) at 4th assault, then Mt Gardinal (7,723 ft) to northeast (September 23), beats of Austrian attacks until September 28.
Asiatic and Egyptian Theaters
Southern Tunisia: 4 French Farmans bomb Senussi base, but 1 crashes.
Naval and Overseas Operations
Adriatic: French submarine Foucault is scuttled while on patrol off Cattaro after being damaged by two Austro-Hungarian aeroplanes. Austrian Lohner flying-boats then land and save crew.
East Africa: General Smuts' columns reach south of Uluguru Hills, and join near, and occupy, Kissaki; Van Deventer approaching the Great Ruaha river towards Mahenge.
Sudi Bay occupied by British naval forces.
Political, etc.
Romania: Crown Council decides to transfer half Transylvanian Armies to face Bulgaria.