First World War in FocusField Marshal Sir Douglas Haig replaces Field Marshal Sir John French as commander of the British Expeditionary Force (BEF).
First use of phosgene gas
The Germans use phosgene gas for the first time against the British at Wieltje, near Ypres.
Siege of Kut begins
The Ottomans besiege British-Indian forces at Kut in Mesopotamia (now Iraq).
Battle of Kosturino
The Battle of Kosturino on the Salonika front ends in a Bulgarian victory over the Allies.
Introduction of new Lee Enfield rifle
The Short Magazine Lee Enfield (SMLE) Mk III*, a cheaper mass-produced version of the British Empire’s iconic Mk III Rifle (adopted in 1907), is introduced for general service.
Serbs defeated
The Serbians are defeated by the invading Central Powers and remnants of their army are evacuated by Allied navies to regroup.
Battle of Ctesiphon
The Battle of Ctesiphon, fought between British and Ottomans forces in Mesopotamia (now Iraq), is inconclusive.
Senussi Revolt begins
Senussi tribesmen, backed by the Ottomans, rise up against the Allies in Italian Libya and Egypt. Although suppressed by the British, the revolt rumbles on until 1917.
Italy and Russia declare war on Bulgaria
France declares war on Bulgaria
Britain declares war on Bulgaria
Bulgaria declares war on Serbia
Machine Gun Corps formed
The British Army forms the Machine Gun Corps to make more effective use of heavy machine guns (primarily the Vickers) on the Western Front.
Serbia invaded again by Central Powers
Serbia is invaded by Germany, Austria-Hungary and their new ally, Bulgaria.
Allies begin landing at Salonika
French, British and Italian troops begin landing at Salonika (now Thessaloniki, in Greece) in the Balkans.
Introduction of Lewis Gun
The British Army officially adopts the Lewis Gun for both land and aircraft use.
Capture of Kut-al-Amara
Following victory at Es Sinn, British-Indian forces capture the town of Kut in Mesopotamia (now Iraq) from Ottoman forces.
Battle of Es Sinn
The Battle of Es Sinn ends in a British-Indian victory over the Ottomans in Mesopotamia (now Iraq).
Battle of Loos
The Battle of Loos on the Western Front sees the British offensive fail at German hands. The 50-watt Trench Set (or BF Set), the British Army’s first reliable radio, was first used during this engagement.
Tsar Nicholas II assumes command of Russian Army
The Russian Tsar Nicholas II replaces Grand Duke Nicholas Nikolayevich as Commander-in-Chief of the Russian Army.
Germany suspends unrestricted submarine warfare
Introduction of Brodie helmet
The British Army adopts the Brodie helmet as its standard head protection for soldiers.
Battles of Scimitar Hill and Hill 60
The last attempt by the British to seize the Gallipoli peninsula is unsuccessful.
Operations in the Swat Valley
The Indian Army defeats a series of tribal uprisings in the Swat Valley on the North-West Frontier of India (now in Pakistan).
Battle of Chunuk Bair
Part of the Gallipoli Campaign: The Battle of Chunuk Bair at Anzac Cove ends in an Ottoman victory.
Battle of the Nek
Part of the Gallipoli Campaign: The Battle of the Nek at Anzac Cove ends in an Australian defeat.
Battle of Sari Bair
Part of the Gallipoli Campaign: The Battle of Sari Bair follows new landings at Suvla.
Battle of Lone Pine
Part of the Gallipoli Campaign: The Battle of Lone Pine ends in an Australian victory.
Germany occupies Warsaw
Pope appeals for peace
Pope Benedict XV appeals to all governments to cease hostilities.
Battle of Shaikh Othman
British-Indian forces defeat the Ottomans at Shaikh Othman near Aden.
German South-West Africa captured
The German forces in South-West Africa (now Namibia) surrender at Khorab.
Battle of Lahij
Ottoman forces secure victory over the British at Lahij near Aden.
Formation of British gas warfare units
The Royal Engineers form Special Companies to oversee Britain’s gas warfare effort.
First aircraft destroyed by synchronised machine-gun
A German Fokker, the first aircraft to be fitted with a device enabling the pilot to fire his machine gun through the arc of the propeller, shoots down a French aircraft.
First use of flamethrowers
The first large-scale use of flamethrowers takes place at Hooge in Belgium, during a German attack on the British lines.
Battle of Gully Ravine
Part of the Gallipoli Campaign: The Battle of Gully Ravine at Cape Helles secures limited British gains.
Battles of the Isonzo
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.
Third Battle of Krithia
Part of the Gallipoli Campaign: The Third Battle of Krithia fails to secure an Allied breakout.
Maudsley psychiatric hospital established
The Maudsley Military Hospital is set up in London to treat cases of shell shock (neurasthenia).
Italy declares war on Austria-Hungary
Battle of Festubert
The Battle of Festubert on the Western Front secures limited British gains at German expense.
South Africans capture Windhoek
Windhoek, the capital of German South-West Africa (now Namibia), is occupied by South African troops.
Battle of Aubers Ridge
A British offensive at Aubers Ridge on the Western Front ends in a German victory.
Lusitania sunk
The British liner ‘Lusitania‘ is sunk off the south coast of Ireland by a German U-boat. The loss of over 120 American lives causes a storm of protest in the United States.
Second Battle of Krithia
Part of the Gallipoli Campaign: The Second Battle of Krithia results in an Allied failure at the hands of the Ottomans.
Introduction of Mills Bomb
The No 5 Grenade (Mills Bomb) is introduced. This is the standard grenade used by British Empire forces for the rest of the war.
First Battle of Krithia
Part of the Gallipoli Campaign: The First Battle of Krithia sees the Allied advance repelled by the Ottomans.
London Pact between the Allies and Italy
The Allies offer Italy territorial gains in any post-war settlement in return for their support.
Gallipoli landings
Allied forces land at Cape Helles on the Gallipoli peninsula to support naval attempts at forcing the Dardanelles.
First British gas mask
Scottish physiologist John Scott Haldane invents the veil respirator, the first British gas mask.
Second Battle of Ypres
The first large-scale use of poison gas by the Germans fails to end the stalemate on the Western Front.
Battle of Shaiba
British-Indian troops stop the Ottomans re-capturing Basra in Mesopotamia (now Iraq).
Introduction of Thomas splint
The introduction of the Thomas splint, named after the Welsh surgeon Hugh Owen Thomas, drastically cuts the numbers of British soldiers dying from broken femurs.
Battle of Neuve Chapelle
After initial success, a British-Indian offensive is halted by the Germans at Neuve Chapelle.
Allies fail to force Dardanelles
The British and French navies unsuccessfully attempt to force the Ottoman-controlled Dardanelles Strait.
Second Battle of the Masurian Lakes
The Second Battle of the Masurian Lakes, in East Prussia, ends in a Russian defeat to the Germans.
German U-boats start attacking merchant shipping
Germany begins submarine warfare against merchant vessels.
Formation of British tunnelling units
The Royal Engineers form Tunnelling Companies to oversee underground warfare.
Ottoman attack on Suez Canal
The Ottomans fail to capture the Suez Canal, a British-controlled shipping route linking the Mediterranean to the Red Sea.
Battle of Dogger Bank
The Royal Navy is victorious against the Germans at the Battle of Dogger Bank in the North Sea.
First Zeppelin raid on Britain
The first Zeppelin (airship) raid on Britain sees King’s Lynn and Great Yarmouth bombed by the Germans.
Invention of Stokes Mortar
The 3-inch Stokes Mortar is invented and soon becomes the standard British Army mortar of the war.
Maritz Rebellion
A Boer rebellion, led by General Manie Maritz against South Africa’s support for Britain and its invasion of German South-West Africa, is eventually suppressed.
