British, Australian and New Zealand forces are victorious at the Battle of Magdhaba in the Sinai peninsula.
Fighting at Verdun, the longest battle of the First World War, comes to an end.
General Robert Nivelle replaces General Joseph Joffre as Commander-in-Chief of the French Army.
David Lloyd George replaces Herbert Asquith as British Prime Minister.
The Austro-Hungarian Emperor Francis Joseph I is succeeded by Charles I.
The Battle of the Somme ends after months of attritional fighting.
The Indian Army begins a punitive expedition against Mohmand tribal raiders on the North-West Frontier of India (now in Pakistan).
Part of the Battle of the Somme: The Battle of the Ancre, the last British attack on the Somme, ends in limited gains.
The French recapture Fort Douaumont from the Germans at Verdun.
Part of the Battle of the Somme: The Battle of Le Transloy ends in stalemate.
The Craiglockhart War Hospital in Edinburgh begins treating officers with shell shock (neurasthenia).
The British capture Karajakois (now Monokklisia in northern Greece) from the Bulgarians on the Salonika front.
Part of the Battle of the Somme: The Battle of Thiepval Ridge sees British gains.
Part of the Battle of the Somme: The Battle of Morval sees British-French gains.
Part of the Battle of the Somme: The Battle of Flers-Courcelette sees the British use tanks for the first time in history.
An Allied offensive against the Bulgarians at Monastir (now Bitola in the Republic of Macedonia) ends in limited gains.
Part of the Battle of the Somme: The British enjoy limited success at the Battle of Ginchy.
Part of the Battle of the Somme: The Battle of Guillemont sees limited British success.
General Paul von Hindenburg replaces General Erich von Falkenhayn as German Chief of Staff.
Romania enters the war on the Allied side, but is defeated within a few weeks.
The First Battle of Doiran on the Salonika front ends in a Bulgarian victory over the Allies.
An Ottoman attack on the British at Romani in the Sinai peninsula fails.
The British use the creeping artillery barrage for the first time during the Battle of the Somme.
Part of the Battle of the Somme: The Battle of Pozières sees limited Australian and British gains.
Part of the Battle of the Somme: The Battle of Fromelles ends in a German victory.
Part of the Battle of the Somme: The Battle of Bazentin Ridge ends in tactical gains for the British.
Part of the Battle of the Somme: The Battle of Delville Wood sees limited South African and British gains.
Part of the Battle of the Somme: The initial phase of the Somme offensive sees French success in the south but heavy British casualties for little gain in the north.
The Battle of the Somme, a Franco-British attack aimed at relieving the pressure at Verdun, is part of a combined Allied offensive against the Central Powers.
Field Marshal Lord Kitchener drowns when HMS ‘Hampshire’ is sunk by a German mine off the Orkney Islands while bound for Russia.
The Arab Revolt against the Ottomans begins in Hejaz (now part of Saudi Arabia).
The Russians launch the Brusilov Offensive against German and Austro-Hungarian forces on the Eastern Front.
A German attack at Mont Sorrel in the Ypres Salient is repelled by British and Canadian forces.
A British-Rhodesian force captures Namema in German East Africa (now Tanzania).
The Battle of Jutland between Britain and Germany ends in stalemate, but the Royal Navy’s control of the North Sea continues.
Three British columns invade German East Africa (now Tanzania) from the north, south and west, but fail to defeat the Germans. A long guerrilla war ensues.
The box respirator is introduced as the British Army’s standard gas mask.
The besieged British-Indian force at Kut in Mesopotamia (now Iraq) surrenders to the Ottomans.
Irish Republicans mount an unsuccessful rising in Dublin against British rule in Ireland.
Major Lawrence Robertson of the Canadian Army performs one of the earliest blood transfusions on the Western Front.
The Royal Navy destroys Germany’s U-68, the first submarine to be sunk with depth charges.
British-Egyptian forces successfully invade and annex the Sultanate of Darfur (now part of Sudan), whose ruler was suspected of having Ottoman sympathies.
Following the seizure of German ships in Lisbon, Germany declares war on Britain’s ally Portugal.
The British fail in another attempt to relieve the besieged town of Kut in Mesopotamia (now Iraq).
The Military Service Act comes into force in the United Kingdom. Men from 18 to 41 years old are liable to be called up for Army service.
The Battle of Verdun begins, an attritional German offensive intended to ‘bleed France white’.
The Allies complete the conquest of German Kamerun (now Cameroon).
The Battle of Hanna in Mesopotamia (now Iraq) ends in an Ottoman victory over British-Indian forces.
The Battle of Wadi in Mesopotamia (now Iraq) ends in an Ottoman victory over British-Indian forces.
The Mediterranean island of Corfu is occupied by the Allies to receive the evacuated Serbian Army.
The Allies complete the evacuation of Gallipoli. The campaign ends in an Ottoman victory.
British forces, marching to relieve the besieged town of Kut in Mesopotamia (now Iraq), defeat the Ottomans at the Battle of Shaik Saad.
Fighting takes place between the Italians and Austro-Hungarians along the Isonzo (now the Soča) valley. A total of 12 battles are fought in this location, wearing down the armies of both nations over the following two years.