| Dates |
Events |
|
| June 28 |
Assassination of Archduke Franz Ferdinand of Austria, the heir to the Austro-Hungarian throne, who is killed in Sarajevo along with his wife, Duchess Sophie.[1] |
Details |
| July 5 |
Austria-Hungary seeks German support for a war against Serbia in case of Russian mobilization. Germany gives assurances of support.[2] |
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| July 23 |
Austria-Hungary sends an ultimatum to Serbia. The Serbian response is seen as unsatisfactory.[3] |
Details |
| July 28 |
Austria-Hungary declares war on Serbia. Russia mobilizes.[4] |
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| July 31 |
Germany warns Russia to stop mobilizing. Russia says mobilization is against Austria-Hungary only. |
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| August 1 |
Germany declares war on Russia.[5] |
|
Italy declares its neutrality.
Germany and the Ottoman Empire sign a secret alliance treaty.[6] |
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| August 2 |
Germany invades Luxembourg. |
Details |
| August 3 |
Germany declares war on France and Belgium.[7] |
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| August 4 |
Germany invades Belgium[8] to outflank the French army. |
Details |
Britain protests the violation of Belgian neutrality, guaranteed by a treaty;
German Chancellor replies that the treaty is just a chiffon de papier (a scrap of paper).
The United Kingdom declares war on Germany.[9] |
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| August 5 |
Montenegro declares war on Austria-Hungary.[10] |
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| The Ottoman Empire closes the Dardanelles. |
|
| August 5–August 16 |
The Germans besiege and then capture the fortresses of Liège, Belgium. |
Details |
| August 6 |
Austria-Hungary declares war on Russia.
Serbia declares war on Germany. |
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| August 7 |
The British Expeditionary Force arrives in France.[11] |
Details |
| August 9 |
Montenegro declares war on Germany. |
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| August 11 |
France declares war on Austria-Hungary. |
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| August 12 |
The United Kingdom declares war on Austria-Hungary. |
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| August 14–August 24 |
Battle of the Frontiers. The Germans obtain a victory against the British Expeditionary Force and France's Fifth Army. |
Details |
| August 16–August 19 |
The Serbs defeat the Austro-Hungarians at the Battle of Cer.[12] |
Details |
| August 17 |
The Russian army enters East Prussia. Battle of Stalluponen. |
Details |
| August 20 |
The Germans attack the Russians in East Prussia. The attack is a failure in addition to being a violation of the Schlieffen Plan.[13] |
Details |
| August 17–September 2 |
Battle of Tannenberg: the Russian army undergoes a heavy defeat by the Germans.[14] |
Details |
| August 20 |
The Germans occupy Brussels. |
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| August 22 |
Austria-Hungary declares war on Belgium. |
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| August 23 |
Japan declares war on Germany. |
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| August 23–August 25 |
Battle of Kraśnik. The Austro-Hungarian First Army defeats the Russian Fourth Army.[15] |
Details |
| August 24–September 7 |
The Germans siege and capture the Maubeuge Fortress. |
Details |
| August 25 |
Japan declares war on Austria-Hungary. |
|
| August 26 |
British and French forces invade Togoland, a German protectorate in West Africa.[16] |
Details |
| August 26–August 27 |
Battle of Le Cateau. Allied retreat. |
Details |
| August 26–September 11 |
Battle of Lemberg. The Russians capture Lviv. |
Details |
| August 27–November 7 |
Battle of Tsingtao: British and Japanese forces capture the German-controlled port of Tsingtao in China. |
Details |
| August 28 |
The Royal Navy wins the First Battle of Heligoland Bight, North Sea. |
Details |
| August 29–August 30 |
Battle of Saint Quentin, aka Battle of Guise. Orderly Allied retreat. |
Details |
| August 30 |
New Zealand occupies German Samoa (later Western Samoa). |
Details |
| September 3–September 11 |
Austro-Hungarian defeat at the Battle of Rava Russka. |
Details |
| September 5–September 12 |
First Battle of the Marne. The German advance on Paris is halted, marking the failure of the Schlieffen Plan.[17] |
Details |
| September 7–September 14 |
First Battle of the Masurian Lakes: The Russian Army of the Neman withdraws from East Prussia with heavy casualties. |
Details |
| September 8–September 17 |
Second Austro-Hungarian attempt at invading Serbia fails. |
|
| September 9 |
Theobald von Bethmann Hollweg lays out Germany's war aims. |
Details |
| September 11–September 21 |
Australian forces occupy German New Guinea.[18] |
Details |
| September 13 |
Troops from South Africa begin invading German South-West Africa. |
Details |
| September 13–September 28 |
The First Battle of the Aisne ends in a substantial draw. The Race to the Sea begins. |
Details |
| September 14 |
Erich von Falkenhayn replaces Helmuth von Moltke the Younger as German Chief of Staff. |
Details |
| September 17 |
The Siege of Przemyśl begins |
Details |
| September 28–October 10 |
The Germans siege and capture Antwerp, Belgium. |
Details |
| September 29–October 31 |
Battle of the Vistula, aka Battle of Warsaw. |
Details |
| October 16–October 31 |
Battle of the Yser. French and Belgian forces secure the coastline of Belgium.[19] |
Details |
| October 19–November 22 |
The First Battle of Ypres ends the Race to the Sea. The Germans are prevented from reaching Calais and Dunkirk. |
Details |
| November 1 |
Russia declares war on the Ottoman Empire. |
|
| Battle of Coronel. Von Spee's German cruiser squadron defeats a Royal Navy squadron under Christopher Cradock.[20] |
Details |
| November 2 |
The United Kingdom begins the naval blockade of Germany. |
Details |
| November 3 |
Montenegro declares war on the Ottoman Empire. |
|
| November 3–November 5 |
Von Lettow-Vorbeck's German colonial forces defeat the British at the Battle of Tanga, German East Africa. |
Details |
| November 5 |
France and the United Kingdom declare war on the Ottoman Empire. |
|
| November 6 |
The Austro-Hungarians enter Belgrade. |
|
| November 9 |
Battle of Cocos, northeast Indian Ocean. The Australian cruiser Sydney destroys the German cruiser Emden.[21] |
Details |
| November 11–December 6 |
Battle of Łódź |
Details |
| November 11 |
Sultan Mehmed V declares Jihad on the Allies.[22] |
|
| December 8 |
Battle of the Falklands. Von Spee's German cruiser squadron is defeated by the Royal Navy.[23] |
Details |
| December 16 |
The German fleet shells Scarborough and Hartlepool, England.[24] |
Details |
| December 24-December 25 |
An unofficial Christmas truce is declared between large numbers of German and French forces.[25] |
Details |
| December 29–January 2, 1915 |
The Russians win the Battle of Sarikamis, Caucasia.[26] |
Details |
| Dates |
Events |
|
| January 2 |
The Russian offensive in the Carpathians begins. It will continue until April 12. |
|
| January 19 |
First Zeppelin raid on Great Britain. |
Details |
| January 24 |
Battle of Dogger Bank between squadrons of the British Grand Fleet and the German Hochseeflotte. |
Details |
| January 28–February 3 |
The Ottomans fail to capture the Suez Canal. |
Details |
| January 31 |
Battle of Bolimov. First German use of chemical weapons.[27] |
Details |
| February 4 |
Germany begins submarine warfare against merchant vessels. |
Details |
| February 7–February 22 |
Second Battle of the Masurian Lakes. The Russian X Army is defeated. |
Details |
| February 19 |
British and French naval attack on the Dardanelles. The Gallipoli Campaign begins.[28] |
Details |
| March 10–March 13 |
Battle of Neuve Chapelle. After an initial success, a British offensive is halted. |
Details |
| March 22 |
The Siege of Przemyśl ends. The Russians capture the fortress. |
Details |
| April 22–May 25 |
At the Second Battle of Ypres, ending in a stalemate. |
Details |
| April 25 |
Allied forces land on Gallipoli.[29] |
Details |
| London Pact between the Entente and Italy. |
Details |
| April 28 |
First Battle of Krithia. The Allied advance is repelled.[30] |
Details |
| May 1–May 3 |
Battle of Gorlice-Tarnów: the German troops under General Mackensen break through the Russian lines in Galicia. |
Details |
| May 6–May 8 |
Second Battle of Krithia. The Allied attempts at advancing are thwarted again.[31] |
Details |
| May 7 |
The British liner Lusitania is sunk by a German U-boat.[32] |
Details |
| May 10 |
Troops from Hungary rout the Russians at Jarosław. Lviv is again in Austrian hands. |
|
| May 12 |
Windhoek, capital of German South-West Africa, is occupied by South African troops.[33] |
Details |
| May 23 |
Italy declares war on Austria-Hungary. |
|
| June 4 |
Third Battle of Krithia. Yet another Allied failure.[31] |
Details |
| The Russians leave Przemyśl. |
Details |
| June 22 |
Mackensen breaks again through the Russian lines in the Lviv area. |
Details |
| June 23–July 7 |
First Battle of the Isonzo. |
Details |
| June 27 |
The Austro-Hungarians re-enter Lviv. |
Details |
| June 28–July 5 |
The British win the Battle of Gully Ravine. |
Details |
| July 9 |
The German forces in South-West Africa surrender. |
Details |
| July 18–August 3 |
Second Battle of the Isonzo. |
Details |
| August 5 |
The Germans occupy Warsaw. |
Details |
| August 6–August 29 |
Battle of Sari Bair, aka the August Offensive. Last and unsuccessful attempt by the British to seize the Gallipoli peninsula.[34] |
Details |
| September 1 |
Germany suspends unrestricted submarine warfare. |
Details |
| September 8 |
Nicholas II removes Grand Duke Nicholas Nikolayevich as Commander-in-Chief of the Russian Army, personally taking that position. |
Details |
| September 19 |
The Germans occupy Vilnius. The Gorlice-Tarnów Offensive ends. |
Details |
| September 25–September 28 |
Battle of Loos. A major British offensive fails. |
Details |
| October 6 |
Serbia is invaded by Germany, Austria-Hungary and Bulgaria. |
Details |
| October 14 |
Bulgaria declares war on Serbia |
|
| October 15 |
The United Kingdom declares war on Bulgaria. |
|
| October 16 |
France declares war on Bulgaria. |
|
| October 18–November 4 |
Third Battle of the Isonzo |
Details |
| October 19 |
Italy and Russia declare war on Bulgaria. |
|
| October 27 |
A French army lands in Salonika and, with the help of British and Italian troops, sets up a Balkan Front. |
|
| November 10–December 2 |
Fourth Battle of the Isonzo |
| November 22–November 25 |
Battle of Ctesiphon, in present-day Iraq.[35] |
Details |
| November 27 |
The Serbian army collapses. It will retreat to the Adriatic Sea and be evacuated by the Italian and French Navies. |
Details |
| December 7 |
The Siege of Kut, Mesopotamia, by the Ottomans begins.[36] |
Details |
| December 19 |
Douglas Haig replaces John French as commander of the British Expeditionary Force. |
Details |
| Dates |
Events |
|
| January 9 |
Battle of Rafa. The British drive the Ottomans out of Sinai. |
Details |
| January 16 |
The German Foreign Secretary Arthur Zimmermann sends a telegram to his ambassador in Mexico, instructing him to propose the Mexican government an alliance against the United States. |
Details |
| February 1 |
Germany resumes unrestricted submarine warfare. |
Details |
| February 23 |
Second Battle of Kut. The British recapture the city. |
Details |
| February 23–April 5 |
The Germans withdraw to the Hindenburg Line. |
Details |
| March 1 |
Arz von Straussenberg replaces Conrad von Hötzendorf as Austro-Hungarian Chief of Staff. |
Details |
| March 8–March 11 |
The British capture Baghdad. |
Details |
| March 15 |
Russia: Czar Nicholas II abdicates. A provisional government is appointed. |
Details |
| March 26 |
First Battle of Gaza. The British attempt to capture the city fails.[42] |
Details |
| April 6 |
The United States of America declares war on Germany.[43] |
|
| April 9–April 12 |
The Canadians obtain a significant victory in the Battle of Vimy Ridge.[44] |
Details |
| April 16–May 9 |
The Second Battle of the Aisne (aka Nivelle Offensive) ends in disaster for both the French army and its commander Robert Nivelle.[45] |
Details |
| April 19 |
Second Battle of Gaza. The Ottoman lines resist a British attack. |
Details |
| April 29–May 20 |
Series of mutinies in the French army.[46] |
Details |
| May 5–May 15 |
Allied offensive on the Salonika Front. |
|
| April 9–May 16 |
Battle of Arras. The British attack a heavily fortified German line without obtaining any strategic breakthrough.[47] |
Details |
| May 12–June 6 |
Tenth Battle of the Isonzo. |
Details |
| May 15 |
Philippe Pétain replaces Robert Nivelle as Commander-in-Chief of the French Army.[48] |
Details |
| May 23 |
Battle of Mount Hermada in the Karst. |
Details |
| June 7–June 8 |
The British recapture Messines Ridge. |
Details |
| June 10–June 29 |
Battle of Mount Ortigara. |
Details |
| June 12 |
Greece: King Constantine I abdicates.[49] |
Details |
| June 25 |
First American troops land in France. |
Details |
| July 1–July 19 |
The Kerensky Offensive fails. It is the last Russian initiative in the war.[50] |
Details |
| July 6 |
Arab rebels led by Lawrence of Arabia seize the Jordanian port of Aqaba.[51] |
Details |
| July 20 |
Corfu Declaration about the future Kingdom of Yugoslavia.[52] |
Details |
| July 31 |
The Battle of Passchendaele (aka Third Battle of Ypres) begins. |
Details |
| August 6–August 20 |
Battle of Mărăşeşti. |
Details |
| August 18–August 28 |
Eleventh Battle of the Isonzo. |
Details |
| September 8 |
Russia: General Kornilov's coup attempt fails. |
Details |
| September 27–September 28 |
Battle of Ramadi, Mesopotamia. |
Details |
| October 24–November 4 |
Battle of Caporetto. The Austro-Hungarians and Germans break through the Italian lines. The Italian army is defeated and falls back on the Piave River. |
Details |
| October 30 |
Italy: Vittorio Emanuele Orlando succeeds Paolo Boselli as Prime Minister. |
Details |
| October 31–November 7 |
Third Battle of Gaza. The British break through the Ottoman lines. |
Details |
| November 2 |
Balfour Declaration: the British government supports plans for a Jewish "national home" in Palestine. |
Details |
| November 5 |
The Allies agree to establish a Supreme War Council at Versailles. |
|
| November 7 |
The October Revolution begins in Russia. The Bolsheviks seize power. |
Details |
| November 8 |
Armando Diaz replaces Luigi Cadorna as Commander-in-Chief of the Italian Army. |
Details |
| November 9–December 28 |
First Battle of the Piave: the Austro-Hungarians and Germans try unsuccessfully to cross the river. |
Details |
| November 10 |
The Battle of Passchendaele (aka Third Battle of Ypres) ends in a stalemate. |
Details |
| November 13 |
France: Paul Painlevé is replaced by Georges Clemenceau as Prime Minister. |
Details |
| November 17 |
Second Battle of Heligoland Bight, North Sea. |
Details |
| November 20–December 3 |
Battle of Cambrai. A British attack fails and the battle results in a stalemate.[53] |
Details |
| December 7 |
The United States declares war on Austria-Hungary. |
| December 8–December 26 |
Battle of Jerusalem. The British enter the city (December 11). |
Details |
| December 23 |
Russia signs an armistice with Germany. |
|
| Dates |
Events |
|
| January 8 |
Woodrow Wilson outlines his Fourteen Points. |
Details |
| February 18 |
Fighting resumes on the Eastern Front. |
|
| February 21 |
The British capture Jericho. |
|
| February 25 |
German troops capture Estonia. |
|
| March 3 |
At Brest-Litovsk, Leon Trotsky signs the peace treaty with Germany.[54] |
Details |
| March 21–March 25 |
First phase of the Spring Offensive (Operation Michael). The Germans obtain a Pyrrhic victory. |
Details |
| March 23–August 7 |
Artillery bombardment of Paris. |
Details |
| March 26 |
French Marshall Ferdinand Foch is appointed Supreme Commander of all Allied forces. |
Details |
| April 1- |
Royal Air Force founded by combining the Royal Flying Corps and the Royal Naval Air Service. |
| April 4 |
Second phase of the Spring Offensive (Operation Georgette). The results are disappointing for the Germans. |
Details |
| May 7 |
Treaty of Bucharest between Romania and the Central Powers. It will never be ratified. |
Details |
| May 27–June 6 |
Third Battle of the Aisne (aka Operation Blücher-Yorck, third phase of the Spring Offensive). After initial gains, the German advance is halted. |
Details |
| June 9–June 12 |
Final phase of the Spring Offensive (Operation Gneiseau). Despite substantial territorial gains, the Germans do not achieve their strategic goals |
Details |
| June 13–June 23 |
Second Battle of the Piave: the Austro-Hungarian offensive is repelled. |
Details |
| July 15–August 5 |
Second Battle of the Marne and last German offensive on the Western Front, which fails when the Germans are counterattacked by the French. |
Details |
| August 8–August 11 |
Battle of Amiens, first phase of the Hundred Days Offensive. |
Details |
| September 12 |
Battle of Havrincourt, a phase of the Hundred Days Offensive. |
Details |
| September 15 |
The Allies break through the Bulgarian lines at Dobro Polje. |
Details |
| September 18–September 19 |
Battle of Doiran, The Bulgarians halt the British and Greek advance. |
Details |
| September 18–October 10 |
Battle of the Hindenburg Line, a phase of the Hundred Days Offensive. The Allies break through the German lines. |
Details |
| September 19–September 21 |
Battle of Megiddo. The British conquer Palestine. |
Details |
| September 26–November 11 |
Meuse-Argonne Offensive, the final phase of the Hundred Days Offensive and of World War I. |
Details |
| September 30 |
Bulgaria signs an armistice with the Allies.[55] |
|
| October 1 |
The British enter Damascus. |
Details |
| October 20 |
Germany suspends submarine warfare. |
Details |
| October 24–November 4 |
Battle of Vittorio Veneto. The Austro-Hungarian army is routed. The Italians enter Trent and land at Triest. |
Details |
| October 29 |
Wilhelm Groener replaces Erich Ludendorff as Hindenburg's deputy. |
Details |
| October 29 |
Germany's Hochseeflotte mutinies.[56] |
Details |
| October 30 |
The Ottoman Empire signs the Armistice of Mudros. |
Details |
| November 3 |
Austria-Hungary signs the armistice with Italy, effective November 4.[57] |
|
| November 9 |
Germany: Kaiser William II abdicates; republic proclaimed.[58] |
Details |
| November 10 |
Austria-Hungary: Kaiser Charles I abdicates. |
Details |
| November 11 |
At 6 am, Germany signs the Armistice of Compiègne. End of fighting at 11 a.m..[59] |
|
| November 12 |
Austria proclaimed a republic. |
|
| November 14 |
Czechoslovakia proclaimed a republic. |
Details |
| German U-boats interned. |
|
| 3 days after the armistice, fighting ends in the East African theater when General von Lettow-Vorbeck agrees a cease-fire on hearing of Germany's surrender. |
Details |
| November 21 |
Germany's Hochseeflotte surrendered to the United Kingdom.[56] |
Details |
| November 22 |
The Germans evacuate Luxembourg. |
|
| November 23 |
9 days after agreeing a cease-fire, General von Lettow-Vorbeck formally surrenders his undefeated army at Abercorn in present-day Zambia. |
Details |
| November 27 |
The Germans evacuate Belgium. |
|
| December 4 |
Yugoslav independence proclaimed.[60] |
Details |