World War I
World War I or the First World War, often abbreviated as WWI or WW1, began on 28 July 1914 and ended on 11 November 1918. Referred to by contemporaries as the "Great War", its belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fighting also expanding into the Middle East, Africa, and parts of Asia. One of the deadliest conflicts in history, an estimated 9 million people were killed in combat, while over 5 million civilians died from military occupation, bombardment, hunger, and disease. Millions of additional deaths resulted from genocides within the Ottoman Empire and the 1918 influenza pandemic, which was exacerbated by the movement of combatants during the war.
|World War I|
Clockwise from the top:
Allied Powers:||Central Powers:|
|Commanders and leaders|
|Total: 42,928,000||Total: 25,248,000|
|68,176,000 (Total all)|
|Casualties and losses|
|Events leading to World War I|
By 1914, the European great powers were divided into the Triple Entente of France, Russia, and Britain; and the Triple Alliance of Germany, Austria-Hungary, and Italy. Tensions in the Balkans came to a head on 28 June 1914 following the assassination of Archduke Franz Ferdinand, the Austro-Hungarian heir, by Gavrilo Princip, a Bosnian Serb. Austria-Hungary blamed Serbia, which led to the July Crisis, an unsuccessful attempt to avoid conflict through diplomacy. Russia came to Serbia's defense following Austria-Hungary's declaration of war on the latter on 28 July, and by 4 August, the system of alliances drew in Germany, France, and Britain, along with their respective colonies. In November, the Ottoman Empire, Germany, and Austria-Hungary formed the Central Powers, while in April 1915, the initially neutral Italy switched sides to join Britain, France, Russia, and Serbia in forming the Allies of World War I.
Facing a war on two fronts, German strategy in 1914 was first to defeat France, then shift its forces to Eastern Europe and knock out Russia in what was known as the Schlieffen Plan. However, Germany's advance into France failed, and by the end of 1914, the two sides faced each other along the Western Front, a continuous series of trench lines stretching from the English Channel to Switzerland that changed little until 1917. By contrast, the Eastern Front was far more fluid, with Austria-Hungary and Russia gaining and then losing large swathes of territory. Other significant theatres included the Middle Eastern Theatre, the Italian Front, and the Balkans Theatre, drawing Bulgaria, Romania, and Greece into the war.
By early 1915 Russia had been seeing defeat after defeat in the twin Battle of Tannenberg and the Battle of the Masurian Lakes. The Russians had suffered around 450,000 casualties in all of those battles, by then their armies were demoralized and the Germans had sent the bulk of their armies towards the Eastern Front. The siege of Przemyśl had been a success for the Russians but by April the Germans had begun drawing up plans to liberate Galicia. By May the Germans had launched the Gorlice–Tarnów offensive, an offensive which eventually turned into a Russian retreat. By the 5th of August, Warsaw had been occupied by the Germans. The battle finally ended in September 1915 with the entirety of Poland and parts of Minsk Governorate being occupied.
Shortages caused by the Allied naval blockade led Germany to initiate unrestricted submarine warfare in early 1917, bringing the previously-neutral United States into the war on 6 April 1917. In Russia, the Bolsheviks seized power in the October Revolution of 1917, and made peace in the Treaty of Brest-Litovsk on 3 March 1918, freeing up a large number of German troops. By transferring these forces to the Western Front, the German General Staff hoped to win a decisive victory before American reinforcements could impact the war, and launched the German spring offensive in March 1918. Despite initial success, it was soon halted by heavy casualties and ferocious defence; in August, the Allies launched the Hundred Days Offensive and although the Imperial German Army continued to fight hard, it could no longer halt their advance.
Towards the end of 1918, the Central Powers began to collapse; Bulgaria signed an armistice on 29 September, followed by the Ottomans on 31 October, then Austria-Hungary on 3 November. Isolated, facing the German Revolution at home and a military on the verge of mutiny, Kaiser Wilhelm abdicated on 9 November, and the new German government signed the Armistice of 11 November 1918, bringing the conflict to a close. The Paris Peace Conference of 1919–1920 imposed various settlements on the defeated powers, with the best-known of these being the Treaty of Versailles. The dissolution of the Russian, German, Ottoman, and Austro-Hungarian empires led to numerous uprisings and the creation of independent states, including Poland, Czechoslovakia, and Yugoslavia. For reasons that are still debated, failure to manage the instability that resulted from this upheaval during the interwar period ended with the outbreak of World War II in September 1939.