The British Empire and the First World War

The First World War was the largest single military undertaking in the history of the British Empire. By the end of the war in November 1918, more than 8.5 million men from across the empire had served in the British forces, of whom nearly 1.2 million had been killed. India, Canada, Australia, New Zealand, South Africa, and the African colonies had all contributed substantial forces, and the empire’s war effort was central to the British victory. The war, in this respect, was an imperial war. It was also a war that transformed the empire. The post-war settlement, embodied in the treaties of 1919, the League of Nations mandate system, and the gradual recognition of dominion autonomy, marked the beginning of the end of the British Empire as a single, centralised imperial system. The war had, in that sense, both created and destroyed the British Empire of the early twentieth century.

The Empire Goes to War

Britain declared war on Germany on 4 August 1914, on behalf of the entire empire. The Dominions — Canada, Australia, New Zealand, South Africa, and Newfoundland — had the formal right to make their own decision, and they did so in the days that followed. Canada’s decision on 23 August 1914 and South Africa’s on 4 September were particularly important, since both involved serious domestic political debates. The Indian declaration of war was made by the British Indian government without any Indian consultation, and the Indian response was mixed: the Indian Army, which had been built up during the war, served with distinction, and the Indian contribution to the war effort was substantial. The Indian casualties of the war — perhaps 60,000 dead and more than 100,000 wounded — were a major contribution to the British war effort.

The imperial war effort was, in its scale, unprecedented. India provided some 1.4 million men, of whom perhaps 60,000 died. Canada provided more than 600,000 men, of whom perhaps 60,000 died. Australia provided more than 400,000 men, of whom perhaps 60,000 died. New Zealand provided more than 100,000 men, of whom perhaps 17,000 died — a casualty rate of nearly 60 percent that is one of the highest in the history of British warfare. South Africa provided more than 130,000 men, including the famous 1st South African Infantry Brigade that fought at Delville Wood in July 1916. The African colonies, including Nigeria, the Gold Coast, Sierra Leone, and the Gambia, provided more than 100,000 men, mostly as porters and labourers, although some served as combat troops in the East African campaign.

The Western Front

The British contribution to the Western Front was the largest single component of the imperial war effort. The British Expeditionary Force (BEF) of 1914, a small professional force of some 100,000 men, was expanded to more than 1.5 million by the end of the war. The Australian and New Zealand Army Corps (ANZAC) was formed in Egypt in 1915 and fought at Gallipoli, on the Western Front, and in Palestine. The Canadian Corps was formed in 1915 and fought at Ypres, at Vimy Ridge, and at the Hundred Days. The Indian Corps served in France in 1914–1915 and in the Middle East in 1916–1918.

The imperial forces on the Western Front were integrated into the British Army, but the dominion forces retained their separate identities. The Australian and Canadian troops, in particular, developed strong national identities in the course of the war, and the ANZAC tradition established at Gallipoli in 1915 became a central element of Australian and New Zealand national identity. The British and dominion forces fought together at the Battle of the Somme in July 1916, the Battle of Passchendaele in July–November 1917, and the Hundred Days offensive of August–November 1918. The Canadian capture of Vimy Ridge in April 1917 and the Australian capture of Mont St Quentin in August 1918 were particularly celebrated imperial achievements.

The Middle East and Africa

The Middle East and African campaigns were the other major component of the imperial war effort. The British campaign in Mesopotamia (modern Iraq), the campaign in Palestine, and the campaign in East Africa were all major imperial undertakings, fought by British, Indian, Australian, and African forces against the Ottoman Empire and its German allies. The British campaign in Mesopotamia, which had begun as a small expedition to secure the oilfields of the Persian Gulf, became a major military operation under the command of General Sir Stanley Maude. The capture of Baghdad in March 1917 was the climax of the campaign, and the subsequent British occupation of Mesopotamia was the foundation of the post-war British mandate.

The East African campaign was the longest in the war, lasting from August 1914 to November 1918. The German colonial forces in German East Africa, under the command of Colonel Paul von Lettow-Vorbeck, fought a masterful guerrilla campaign against the British and imperial forces. The British eventually had to deploy some 200,000 men, including substantial numbers of Indian and African troops, to defeat the German force. The campaign was, in many respects, a side-show of the First World War, but it was a side-show that cost the lives of perhaps 20,000 Africans and exposed the limits of British colonial administration in East Africa.

The Naval War

The naval war was, in its scale, the most significant single component of the British war effort. The Royal Navy, the largest navy in the world at the outbreak of the war, was the principal instrument of British maritime supremacy. The British blockade of Germany, which had been in place since the outbreak of war, was a major contribution to the British victory, and the British naval supremacy in the Atlantic was decisive in preventing German access to the markets of the Americas and the empire. The Battle of Jutland, fought on 31 May–1 June 1916, was the largest naval battle of the war, and although the battle was tactically inconclusive, the strategic position of the German High Seas Fleet was effectively ended by the battle.

The naval war was a global war, fought on every ocean. The German East Asia Squadron, under the command of Vice Admiral Maximilian von Spee, was destroyed at the Battle of the Falkland Islands in December 1914. The German raiders, which operated from German East Africa and the Pacific, were a serious threat to British merchant shipping, and the British were forced to deploy substantial resources to counter them. The war in the Mediterranean, the Red Sea, and the Indian Ocean was, in important ways, an imperial war, fought by British, Indian, Australian, and Japanese forces against the Ottoman and German empires.

The War and the Empire

The First World War was, in its consequences, a major turning point in the history of the British Empire. The post-war settlement, embodied in the treaties of 1919 and the League of Nations mandate system, was a significant expansion of the British imperial system. The mandates of Palestine, Transjordan, Iraq, Tanganyika, Cameroon, Togoland, South West Africa, and the Pacific islands added substantially to the British imperial system. The German colonial empire was effectively dismantled, and the Japanese, British, French, Belgian, and South African mandates were the legal basis of the new colonial order.

The war, however, also produced the political conditions for the dismantling of the British Empire. The Indian contribution to the war effort was a major argument for Indian self-government, and the Montagu-Chelmsford reforms of 1919 and the Government of India Act of 1935 were significant steps in that direction. The Egyptian revolution of 1919 and the subsequent British recognition of Egyptian independence in 1922 was a further sign of the political changes produced by the war. The Irish War of Independence, which began in 1919, and the Irish Free State, established in 1922, were the most dramatic political consequences of the war. The dominion autonomy established by the Statute of Westminster in 1931 was a further step in the same direction. The British Empire of the post-war period was, in many ways, a different kind of empire from the British Empire of the pre-war period.

Historiographical Note

The historiography of the British Empire and the First World War has been substantially revised since the 1990s. The older tradition, of which the work of C. E. Callwell and the official histories is representative, treated the war as a British imperial war, in which the empire had made a substantial contribution to the British victory. The more recent scholarship, of which the work of Hew Strachan, David French, John Keegan, and the contributors to the Oxford History of the British Empire is the most distinguished representative, has produced a more nuanced picture. The war, on this more recent view, was an imperial war, but it was also a war that transformed the empire. The British imperial forces, in particular, played a major role in the Western Front, and the Australian, Canadian, and New Zealand forces developed a strong sense of national identity in the course of the war. The post-war settlement, in this context, marked the beginning of the end of the British Empire as a single, centralised imperial system. The current generation of historians, of whom the work of Robert Gerwarth, the contributors to The Cambridge History of the First World War (the relevant volume), and the work of the Australian historian Christopher Pugsley are representative, has produced a more integrated picture. The British Empire and the First World War, on this most recent view, were mutually constitutive: the empire was a major contributor to the war effort, and the war was a major contributor to the end of the empire.

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