"World War One", "Great War", and "WW1" redirect here.
For other uses, see World War One
(disambiguation), Great War (disambiguation), and WW1 (album).
World War I
Clockwise from the top: The aftermath of shelling during the Battle of the Somme, Mark V tanks cross
the Hindenburg Line, HMS Irresistible sinks after hitting a mine in the Dardanelles, a British Vickers machine guncrew
wears gas masks during the Battle of the Somme, Albatros D.III fighters of Jagdstaffel 11
Date 28 July 1914 – 11 November 1918
(4 years, 3 months and 2 weeks)
Peace treaties[show]
Location Europe, Africa, the Middle East, the Pacific
Islands, China, Indian Ocean, and off the coast of
South and North America
Result
Allied Powers victory
Central Powers' victory on the Eastern
Front nullified by defeat on the Western
Front
Fall of the German, Russian, Ottoman,
and Austro-Hungarianempires
Russian Civil War and foundation of
the Soviet Union
Formation of new countries in Europe and
the Middle East
Transfer of German colonies and regions of
the former Ottoman Empireto other powers
Establishment of the League of Nations.
(more...)
Belligerents
Central Powers
Allied Powers
German Empire
France
Austria-Hungary
British Empire
Ottoman Empire
Russia (until 1917)
Bulgaria (1915–18)
Serbia
...and co-belligerents
Belgium
Montenegro
Japan
Italy (1915–18)
United States (1917–18)
Romania (1916–18)
Portugal (1916–18)
Hejaz (1916–18)
China (1917–18)
Greece (1917–18)
Siam (1917–18)
...and others
Commanders and leaders
Allied leaders Central Powers leaders
Raymond Poincaré Wilhelm II
Georges Clemenceau Franz Joseph I †
H. H. Asquith Karl I
David Lloyd George Mehmed V †
Nicholas II Mehmed VI
Victor Emmanuel III Three Pashas
Vittorio Orlando Ferdinand I
Woodrow Wilson ...and others
Yoshihito
Peter I
Ferdinand I
Eleftherios Venizelos
...and others
Strength
12,000,000 13,250,000
8,841,541[1][2] 7,800,000
8,660,000[3] 2,998,321
5,615,140 1,200,000
4,743,826 Total: 25,248,321[4]
1,234,000
800,000
707,343
380,000
250,000
50,000
Total: 42,959,850[4]
Casualties and losses
Military dead: 5,525,000 Military dead: 4,386,000
Military wounded:12,831,500 Military wounded:8,388,000
Total: 18,356,500 KIA, WIA and MIA Total: 12,774,000 KIA, WIA and MIA
Civilian dead: 4,000,000 Civilian dead: 3,700,000
...further details. ...further details.
show
v
t
e
Theatres of World War I
Events leading to World War I
Triple Alliance 1882
Franco-Russian Alliance 1894
Anglo-German naval arms race 1898–1912
Venezuela Naval Blockade 1902–1903
Entente Cordiale 1904
Russo-Japanese War 1904–1905
First Moroccan Crisis 1905–1906
Anglo-Russian Entente 1907
Bosnian crisis 1908–1909
Agadir Crisis 1911
Italo-Turkish War 1911–1912
Balkan Wars 1912–1913
Assassination of Franz Ferdinand 1914
July Crisis 1914
v
t
e
World War I (often abbreviated as WWI or WW1), also known as the First World War,
the Great War, or the War to End All Wars,[5] was a global war originating in Europe that lasted
from 28 July 1914 to 11 November 1918. More than 70 million military personnel, including 60
million Europeans, were mobilised in one of the largest wars in history.[6][7] Over nine
million combatantsand seven million civilians died as a result of the war (including the victims of
a number of genocides), a casualty rate exacerbated by the belligerents' technological and
industrial sophistication, and the tactical stalemate caused by gruelling trench warfare. It was one
of the deadliest conflicts in history and precipitated major political change, including
the Revolutions of 1917–1923 in many of the nations involved. Unresolved rivalries at the end of
the conflict contributed to the start of the Second World War twenty-one years later.[8]
The war drew in all the world's economic great powers,[9] assembled in two opposing alliances:
the Allies (based on the Triple Entente of the Russian Empire, the French Third Republic, and
the United Kingdom of Great Britain and Ireland) versus the Central
Powers of Germany and Austria-Hungary. Although Italy was a member of the Triple
Alliance alongside Germany and Austria-Hungary, it did not join the Central Powers, as Austria-
Hungary had taken the offensive against the terms of the alliance.[10] These alliances were
reorganised and expanded as more nations entered the war: Italy, Japan and the United
States joined the Allies, while the Ottoman Empire and Bulgaria joined the Central Powers.
The trigger for the war was the assassination of Archduke Franz Ferdinand of Austria, heir to the
throne of Austria-Hungary, by Yugoslav nationalist Gavrilo Princip in Sarajevo on 28 June 1914.
This set off a diplomatic crisis when Austria-Hungary delivered an ultimatum to the Kingdom of
Serbia[11][12] and, as a result, entangled-international-alliances, formed over the previous decades,
were invoked. Within weeks the major powers were at war, and the conflict soon spread around
the world.
Russia was the first to order a partial mobilisation of its armies on 24–25 July, and when on 28
July Austria-Hungary declared war on Serbia, Russia declared general mobilisation on 30
July.[13] Germany presented an ultimatum to Russia to demobilise, and when this was refused,
declared war on Russia on 1 August. Being outnumbered on the Eastern Front, Russia urged its
Triple Entente ally France to open up a second front in the west.
Japan entered the war on the side of the Allies on 23 August 1914, seizing the opportunity of
Germany's distraction with the European War to expand its sphere of influence in China and the
Pacific.
Over forty years earlier in 1870, the Franco-Prussian War had ended the Second French
Empire and France had ceded the provinces of Alsace-Lorraine to a unified Germany. Bitterness
over that defeat and the determination to retake Alsace-Lorraine made the acceptance of
Russia's plea for help an easy choice, so France began full mobilisation on 1 August and, on 3
August, Germany declared war on France. The border between France and Germany was
heavily fortified on both sides so, according to the Schlieffen Plan, Germany then invaded neutral
Belgium and Luxembourg before moving towards France from the north, leading the United
Kingdom to declare war on Germany on 4 August due to their violation of Belgian neutrality.[14][15]
After the German march on Paris was halted in the Battle of the Marne, what became known as
the Western Front settled into a battle of attrition, with a trench line that changed little until 1917.
On the Eastern Front, the Russian army led a successful campaign against the Austro-
Hungarians, but the Germans stopped its invasion of East Prussia in the battles
of Tannenberg and the Masurian Lakes. In November 1914, the Ottoman Empire joined the
Central Powers, opening fronts in the Caucasus, Mesopotamia, and the Sinai Peninsula. In 1915,
Italy joined the Allies and Bulgaria joined the Central Powers. Romania joined the Allies in 1916.
After the sinking of seven US merchant ships by German submarines, and the revelation that the
Germans were trying to get Mexico to make war on the United States, the US declared war on
Germany on 6 April 1917.
The Russian government collapsed in March 1917 with the February Revolution, and
the October Revolution followed by a further military defeat brought the Russians to terms with
the Central Powers via the Treaty of Brest-Litovsk, which granted the Germans a significant
victory. After the stunning German Spring Offensive along the W
