This article is about the major war of 1914–1918. For other uses, see World War One (disambiguation) and Great War (disambiguation).
"WW1" and "WWI" redirect here. For the album by White Whale, see WWI (album).

World War I

Clockwise from top: trenches on the Western Front; a British Mark IV Tank crossing a trench; Royal Navy battleship HMS Irresistible sinking after striking a mine at the Battle of the Dardanelles; a Vickers machine gun crew with gas masks, and German Albatros D.III biplanes
Date 28 July 1914 – 11 November 1918 (Armistice)
Treaty of Versailles signed 28 June 1919
(4 years and 11 months)
Treaty of Saint-Germain-en-Laye signed 10 September 1919
Treaty of Neuilly-sur-Seine signed 27 November 1919
Treaty of Trianon signed 4 June 1920
Treaty of Sèvres signed 10 August 1920
Location Europe, Africa, the Middle East, the Pacific Islands, China and off the coast of South and North America
Result Allied victory
End of the German, Russian, Ottoman, and Austro-Hungarian empires
Formation of new countries in Europe and the Middle East
Transfer of German colonies and regions of the former Ottoman Empire to other powers
Establishment of the League of Nations. (more...)
Belligerents
Allied (Entente) Powers France British Empire Australia Canada India Newfoundland New Zealand South Africa Southern Rhodesia Russian Empire (1914–17) Italy (1915–18) United States (1917–18) Serbia Japan Belgium Greece (1917–18) Romania (1916–18) Portugal (1916–18) Brazil (1917–18)
...and others
Central Powers Germany Austria-Hungary Ottoman Empire Bulgaria (1915–18)
Co-belligerents
Jabal Shammar
...and others
Commanders and leaders Raymond Poincaré George V Nicholas II Victor Emmanuel III Woodrow Wilson Ferdinand of Romania Taishō Peter I Albert I Venceslau Brás
...and others Wilhelm II Franz Joseph I (1914–16) Karl I (1916–18) Mehmed V (1914–18) Mehmed VI (1918) Ferdinand I
...and others
Strength
[1] 12,000,000 8,841,541[2][3] 8,660,000[4] 5,615,140 4,743,826 1,234,000 800,000 707,343 380,000 250,000
Total: 42,959,850
[1]
13,250,000 7,800,000 2,998,321 1,200,000
Total: 25,248,321
Casualties and losses
Military dead:
5,525,000
Military wounded:
12,831,500
Military missing:
4,121,000
Total:
22,477,500 KIA, WIA or MIA ...further details. Military dead:
4,386,000
Military wounded:
8,388,000
Military missing:
3,629,000
Total:
16,403,000 KIA, WIA or MIA ...further details.
[show] v t e
Theatres of World War I
World War I (WWI) was a global war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918. It was predominantly called the World War or the Great War from its occurrence until the start of World War II in 1939, and the First World War or World War I thereafter. It involved all the world's great powers,[5] which were assembled in two opposing alliances: the Allies (based on the Triple Entente of the United Kingdom, France and Russia) and the Central Powers (originally the Triple Alliance of Germany, Austria-Hungary and Italy; but, as Austria–Hungary had taken the offensive against the agreement, Italy did not enter into the war).[6] These alliances both reorganised (Italy fought for the Allies) and expanded as more nations entered the war. Ultimately, more than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history.[7][8] More than 9 million combatants were killed, largely because of technological advancements that led to enormous increases in the lethality of weapons without corresponding improvements in protection or mobility. It was the sixth-deadliest conflict in world history, subsequently paving the way for various political changes, such as revolutions in many of the nations involved.[9]
Long-term causes of the war included the imperialistic foreign policies of the great powers of Europe, including