History of the United Kingdom during the First World War

Britain in the First World War

1914 – 1918 (1919)
British First World War propaganda poster
Preceded by	Edwardian era
Followed by	Interwar Britain
Monarch	George V
Leader(s)	Civil H. H. Asquith David Lloyd George Army William Robertson John French Douglas Haig Royal Navy Jackie Fisher Henry Jackson John Jellicoe Rosslyn Wemyss RNAS & RFC David Henderson Frederick Sykes Hugh Trenchard Godfrey Paine

The United Kingdom of Great Britain and Ireland was one of the Allied Powers during the First World War of 1914–1918, fighting against the Central Powers (the German Empire, the Austro-Hungarian Empire, the Ottoman Empire and the Kingdom of Bulgaria). The state's armed forces were reorganised—the war marked the creation of the Royal Air Force, for example—and increased in size because of the introduction, in January 1916, of conscription for the first time in the kingdom's history as well as the raising of what was, at the time, the largest all-volunteer army in history, known as Kitchener's Army, of more than two million men. The outbreak of war has generally been regarded as a socially unifying event, although this view has been challenged by more recent scholarship. In any case, responses in Great Britain in 1914 were similar to those amongst populations across Europe.

On the eve of war, there was serious domestic unrest in the UK (amongst the labour and suffrage movements and especially in Ireland) but much of the population rapidly rallied behind the government. Significant sacrifices were made in the name of defeating the Empire's enemies and many of those who could not fight contributed to philanthropic and humanitarian causes. Fearing food shortages and labour shortfalls, the government passed legislation such as the Defence of the Realm Act 1914, to give it new powers. The war saw a move away from the idea of "business as usual" under prime minister H. H. Asquith, and towards a state of total war (complete state intervention in public affairs) under David Lloyd George, the first time this had been seen in Britain. The war also witnessed the first aerial bombardments of cities in Britain.