World War I

World War I was a conflict fought from 1914 to 1918 between two alliances. The Allied Powers, sometimes called the Entente, were led by France, the British Empire and the Russian Empire, and were later joined by Italy, Japan, the United States and many other states. The Central Powers were Germany, Austria-Hungary, the Ottoman Empire and Bulgaria.

At the time people called it simply 'the Great War'. The name 'First World War' became common only after a second world war broke out in 1939. The word 'world' fits because the fighting and its effects reached far beyond Europe: colonies in Africa and the Pacific changed hands, armies fought across the Middle East, and soldiers and labourers were brought from India, Africa, China, Vietnam, Australia, New Zealand, Canada and the Caribbean.

This was the first great war fought with the full power of industrial societies. Factories produced shells, machine guns, barbed wire, poison gas, tanks, submarines and aeroplanes in huge quantities. Railways carried millions of men to the fronts. Whole economies were reorganised around the war, and women took over many jobs in factories and offices. Historians sometimes call this 'total war', because it demanded the effort of whole populations and not just armies.

On 28 June 1914 Archduke Franz Ferdinand, heir to the throne of Austria-Hungary, and his wife Sophie were shot dead in Sarajevo, in Bosnia, by Gavrilo Princip, a young Bosnian Serb who belonged to a group seeking to free South Slavs from Austro-Hungarian rule. Austria-Hungary blamed Serbia and, after securing a promise of support from Germany (often called the 'blank cheque'), sent Serbia a harsh ultimatum. On 28 July it declared war.

Within about a week the local crisis became a European war. Russia, which saw itself as the protector of Serbia and of Slavic peoples, began to mobilise its army. Germany declared war on Russia on 1 August and on Russia's ally France on 3 August. Germany's war plan, associated with the earlier chief of staff Alfred von Schlieffen, called for a quick knockout blow against France through neutral Belgium. When German troops entered Belgium, Britain declared war on Germany on 4 August.

Behind this chain of decisions lay deeper causes that historians still weigh differently: a system of rival alliances (the Triple Alliance and the Triple Entente); a naval arms race between Britain and Germany; competition for colonies; aggressive nationalism, especially in the Balkans, where the Ottoman Empire's retreat had left disputed lands; military plans that relied on mobilising quickly; and leaders in several capitals who believed that war, if it came, would be short and might even solve their problems at home.

Each state entered the war for its own reasons. Austria-Hungary wanted to crush Serbian nationalism, which it saw as a threat to a multinational empire. Germany feared being surrounded by France and Russia and backed its only reliable great-power ally. Russia would not abandon Serbia a second time after earlier humiliations in the Balkans. France was bound to Russia by alliance. Britain cited the guarantee of Belgian neutrality and also feared German domination of the continent.

Others joined later. The Ottoman Empire entered on the German side in late 1914. Japan, allied with Britain since 1902, declared war on Germany in August 1914 and captured the German-held port of Qingdao in China and German islands in the Pacific. Italy, though formally allied to Germany and Austria-Hungary, joined the Allies in 1915 after being promised territory. Bulgaria joined the Central Powers in 1915, Romania the Allies in 1916. The United States entered in April 1917, angered by German unrestricted submarine warfare and by the Zimmermann telegram, in which Germany proposed an alliance with Mexico. China declared war on Germany in 1917 and sent about 140,000 labourers to France.

Colonial empires brought their subjects into the war. Well over a million men from British India served, many on the Western Front, in Mesopotamia and in East Africa. France recruited soldiers from West and North Africa, Madagascar and Indochina. In East Africa both sides relied on hundreds of thousands of African porters, known as carriers, huge numbers of whom died of disease, hunger and exhaustion. Their stories were long left out of the European memory of the war.

In August 1914 German armies swept through Belgium into northern France. Belgian civilians suffered mass executions and the burning of towns such as Leuven (Louvain), events that became central to Allied propaganda. In early September French and British forces stopped the advance at the First Battle of the Marne, close to Paris. Both sides then tried to outflank each other to the north, in the so-called 'race to the sea'. By the end of 1914 a continuous line of trenches ran from the Belgian coast to the Swiss border.

For the next three and a half years this front barely moved. Defence had the advantage: machine guns, rapid-firing artillery and barbed wire could cut down attacking infantry faster than reinforcements could exploit a gap. Commanders tried ever larger artillery bombardments and new weapons. Germany first used chlorine gas on a large scale at Ypres in April 1915. At Verdun in 1916 the German army attacked a French fortress city in a ten-month battle; French and German losses together are usually estimated at around 700,000 killed, wounded and missing. On the first day of the British-led Somme offensive, 1 July 1916, the British Army suffered about 57,000 casualties, including some 19,000 dead, the worst single day in its history.

In 1917 the French Nivelle offensive failed and was followed by widespread refusals to attack in the French army, often called the mutinies. The British fought the long and muddy Third Battle of Ypres (Passchendaele). Tanks, first used by the British on the Somme in 1916, were used en masse at Cambrai in 1917. Gradually both sides developed more flexible tactics: infiltration by small assault groups, creeping barrages, closer cooperation between infantry, artillery, tanks and aircraft.

On the Eastern Front distances were far greater and the lines moved more. Russia invaded East Prussia in 1914 but was heavily defeated at Tannenberg. Austria-Hungary suffered great losses against Russia in Galicia and against Serbia. In 1915 German and Austro-Hungarian forces broke through at Gorlice–Tarnów and pushed Russia out of Poland. In 1916 the Russian Brusilov offensive nearly broke the Austro-Hungarian army. Serbia was overrun in late 1915; its army and many civilians retreated across the Albanian mountains in winter, with terrible losses.

Italy fought Austria-Hungary in the Alps and along the Isonzo river in a dozen battles, suffered a disastrous defeat at Caporetto in 1917, and won at Vittorio Veneto in 1918. Against the Ottoman Empire, the Allies landed at Gallipoli in 1915 in an attempt to seize the straits to Constantinople; after eight months they withdrew. For Australia and New Zealand, the landing of 25 April 1915 became a founding moment of national memory (Anzac Day), and for Turkey the successful defence is linked to the rise of Mustafa Kemal (later Atatürk). British and Indian forces fought in Mesopotamia, where a whole army surrendered at Kut in 1916, and later took Baghdad (1917) and Jerusalem (December 1917). An Arab revolt, begun in 1916 in the Hejaz with British support, fought the Ottomans in Arabia and Syria.

At sea, the British blockade slowly strangled German imports of food and raw materials. The only great fleet battle, Jutland (1916), was indecisive. Germany answered with submarine warfare against merchant shipping; the sinking of the liner Lusitania in 1915 and the return to unrestricted submarine warfare in 1917 helped bring the United States into the war. In Africa, Allied forces seized German Togo, Cameroon and South West Africa, while in German East Africa a guerrilla campaign under Paul von Lettow-Vorbeck continued until after the armistice.

The war transformed life behind the lines. Governments took control of industry, food supplies and labour, introduced rationing and censorship, and in many countries introduced or expanded conscription. Women entered munitions factories, transport and offices in large numbers. In Germany and Austria-Hungary the blockade and poor harvests led to severe food shortages, especially in the 'turnip winter' of 1916–17; historians disagree on how many civilian deaths should be attributed to the blockade, with contemporary German estimates of several hundred thousand now treated with caution.

The worst crime against civilians was the Armenian genocide. From 1915 the Ottoman government, led by the Committee of Union and Progress, deported Armenians from Anatolia toward the Syrian desert, with mass killings, death marches and starvation. Estimates of Armenian deaths generally range from about 600,000 to over 1 million, with some figures higher. Assyrian and Greek Christian communities also suffered mass violence. The Turkish state has long rejected the term genocide, while most genocide scholars and many governments use it; this dispute remains politically sensitive.

The war also spread epidemics and hunger. A severe influenza pandemic, often called the 'Spanish flu', swept the world in 1918–1920, helped by troop movements; it killed tens of millions of people worldwide, more than the war itself, but it is usually counted separately from war deaths. Famine struck parts of the Ottoman Middle East, including Mount Lebanon, and East Africa.

In 1917 the balance changed. In Russia, war weariness, hunger and defeat led to the February Revolution, which ended the monarchy, and then to the Bolshevik seizure of power in October under Lenin. The new government made a separate peace with the Central Powers at Brest-Litovsk in March 1918, giving up vast territories. At almost the same time the United States entered the war, bringing fresh troops, money and supplies to the Allies.

Germany used troops freed from the east for a great spring offensive in 1918. It gained more ground than any attack since 1914 but could not break the Allies, and it exhausted the German army. From August 1918 the Allies, now with growing American forces, advanced steadily in what became known as the Hundred Days Offensive. Bulgaria, the Ottoman Empire and Austria-Hungary sought armistices in September–November. In Germany sailors mutinied, revolution broke out, and Kaiser Wilhelm II abdicated. The armistice took effect at 11 a.m. on 11 November 1918.

Estimates of total deaths usually range from about 15 to 22 million, including roughly 9–11 million soldiers. Germany, Russia, France and Austria-Hungary each lost well over a million military dead; the Ottoman Empire's total losses, including civilians, were proportionally among the highest. Around 20 million more were wounded, many permanently disabled. These figures are approximate: record-keeping collapsed in several countries, and deaths of colonial carriers and labourers were often not counted at all.

The victors met in Paris in 1919. The Treaty of Versailles with Germany, signed on 28 June 1919, took away German colonies and territory, limited its army, required reparations, and included Article 231, which made Germany accept responsibility for the loss and damage caused by the war (the 'war guilt clause'). Separate treaties dealt with Austria (Saint-Germain), Bulgaria (Neuilly), Hungary (Trianon) and the Ottoman Empire (Sèvres, later replaced by Lausanne in 1923 after the Turkish War of Independence). The League of Nations was founded to prevent future wars.

Four empires disappeared: the German, Austro-Hungarian, Russian and Ottoman. New or restored states appeared in Central and Eastern Europe, including Poland, Czechoslovakia, Yugoslavia and the Baltic states. In the Middle East, former Ottoman lands were placed under British and French 'mandates', including Iraq, Syria, Lebanon and Palestine, following wartime agreements such as Sykes–Picot (1916) and the Balfour Declaration (1917), which left conflicting promises to Arabs and to the Zionist movement.

US President Woodrow Wilson's call for 'self-determination' inspired colonised peoples, but the peace conference largely applied it only in Europe. In Korea, then under Japanese rule, the March First Movement of 1919 declared independence in mass peaceful demonstrations that were violently suppressed. In China, the decision to give Germany's rights in Shandong to Japan sparked the May Fourth Movement. In Egypt and India, too, 1919 saw major protests. Many historians argue that the settlement's bitterness, the economic chaos of the post-war years and the brutalisation of politics helped prepare the way for fascism, the Second World War and later conflicts in the Middle East, although how directly the treaty 'caused' the next war is debated.

Memory of the war varies enormously. In Britain, France and Belgium it is remembered as a vast tragedy, marked by Remembrance Day or Armistice Day on 11 November, war memorials in nearly every town, the red poppy, and tombs of the Unknown Soldier in London and Paris. Verdun became a symbol for France; the Somme and Passchendaele for Britain. In Britain an influential image, strengthened by the war poets such as Wilfred Owen and Siegfried Sassoon and later by popular culture, is of brave soldiers sent to futile deaths by incompetent generals ('lions led by donkeys'). Many military historians since the 1990s have challenged this picture, arguing that the British army learned and adapted and that victory in 1918 was real.

In Germany memory was divided and politically explosive. Defeat, the Versailles treaty and the myth that the army had been 'stabbed in the back' by revolutionaries at home were exploited by the nationalist right and by the Nazis. After 1945 the First World War was overshadowed by the Second. For Australia and New Zealand, Gallipoli became a story of national birth; for Canada, Vimy Ridge (1917). In Turkey the Gallipoli victory is part of the founding story of the republic. In Russia the war was long overshadowed by the Revolution and Civil War and was only commemorated more fully after the Soviet era.

Elsewhere the war is remembered through the experience of empire. In India, the service of more than a million soldiers is now increasingly commemorated, but it is also tied to the disappointment of 1919, including the Amritsar massacre. In East Asia the war is remembered less for battles than for its consequences: Japan's gains in China and the Pacific, the Twenty-One Demands of 1915, the May Fourth Movement, and, in Korea, the March First Movement. African memory, including that of the carriers, was neglected for decades and has only recently received serious research and public attention.

The First World War produced an enormous documentary record. Governments kept diplomatic correspondence, military orders, war diaries of units, and statistics of casualties and production. After 1918 several governments published selections of their pre-war diplomatic documents, partly to defend themselves against blame for the war; historians have since learned to read these collections critically, because documents were chosen and sometimes edited.

Millions of letters, diaries and photographs by ordinary soldiers and civilians survive, many now digitised by national archives and libraries. Soldiers' writing, including trench newspapers and memoirs such as Erich Maria Remarque's novel All Quiet on the Western Front (1928), shaped public memory, though memoirs written years later are shaped by hindsight. Official histories written by the general staffs of the major armies are indispensable for operations but often defend commanders' reputations.

Sources for the non-European and colonial sides of the war are more scattered: records of recruitment and labour corps, censored letters of Indian soldiers held in British archives, missionary reports, Ottoman archives (whose access and interpretation have been contested, especially concerning the Armenian genocide), and oral traditions in Africa. Casualty figures depend heavily on which sources are used, which is why reliable reference works give ranges rather than exact numbers.

The question of responsibility has dominated the historiography. Between the wars, many historians rejected the Versailles judgment and argued that all powers had 'slid' into war. In 1961 the German historian Fritz Fischer, in Griff nach der Weltmacht (published in English as Germany's Aims in the First World War), argued that Germany's leaders had wide expansionist aims and bore the main responsibility for the outbreak of war. The 'Fischer controversy' transformed German historiography and prompted work on the domestic roots of foreign policy.

Later research broadened the focus. Some historians emphasise Austria-Hungary's decision to make war on Serbia; others stress Russian mobilisation, French support for Russia, or British ambiguity. Christopher Clark's The Sleepwalkers (2012) described the July Crisis as a shared process in which decision-makers in several capitals, focused on their own fears, failed to see the catastrophe they were creating; critics argue that this approach spreads responsibility too evenly and underplays German and Austro-Hungarian choices. The debate is not only about blame but about how to explain decisions made under uncertainty.

Since the 1970s cultural historians have asked how people experienced and remembered the war. Paul Fussell's The Great War and Modern Memory (1975) argued that the war shaped modern irony and literary consciousness; Jay Winter and others have studied mourning and commemoration. A newer 'global' or 'transnational' turn, visible in Hew Strachan's work and many recent studies, stresses that the war began in the Balkans, reached Africa, Asia and the Middle East, did not really end in 1918 in Eastern Europe and Anatolia, and was deeply tied to empire. Historians also debate whether it makes sense to speak of a 'Thirty Years' War' from 1914 to 1945.