While its pre-war government had been prepared to appease Hitler to avoid war, Britain did not enter the war entirely unprepared. The appeasement period had given time for some rearmament, and most importantly for work to be completed on some vital technological developments, particularly radar. Aircraft production was increased from 1934 and contingency arrangements made to deal with aerial bombardment. Shadow factories capable of conversion to military production were built alongside civilian ones from 1936 and 27 new arms works were built between 1936 and 1939. Limited conscription was introduced in April 1939. However, Britain’s army was still not fully mobilised when war broke out, and was ill-equipped. The retreat from Dunkirk saved the bulk of the Army, but most of its heavy weapons had been left behind. As Britain’s armed forces were expanded, American supply of aircraft and tanks in particular was vital.

The blitz of London in 1940–41 and the later attack of V1 ‘flying bombs’ and V2 missiles caused great damage, but failed to cause a collapse of morale – if anything they strengthened it – and in fact greater proportional damage was caused in the raids on smaller cities such as Coventry or Plymouth, and in the ‘Baedeker’ raids on cities of cultural significance that were lightly defended.

Children were evacuated at the start of the war, and though they began to drift back after the main blitz ended in May 1941, this was part of a major social phenomenon of the war: the erosion of Britain’s traditional class structure, and also of the equally strong regional divisions of the nation. Measures to maintain morale emphasised that the war was being fought for a better future, and the mobilisation of women, the centralised management of labour under the control of the Minister of Labour, former union leader Ernest Bevin, and the unsettling arrival of large numbers of American GIs (including 130,000 blacks) all added to a developing public opinion in favour of measures of social and economic reform. This was shown in the popularity of the proposals for a national insurance system in the Beveridge report and for educational reform.

The major parties agreed an electoral truce for the duration of the war, though discontent with the conduct of the war and the desire for social change produced a number of by-election results that rejected government candidates in favour of independents. The Labour Party had refused to serve under Chamberlain, but agreed to join a coalition when Churchill succeeded him in May 1940 after the debacle in Norway. Churchill was determined that Britain would destroy Nazi Germany. Thus, 48 hours after the Germans reached the Channel, the Emergency Powers Act signalled the intention to mobilise the country fully for the war effort: all people, property and resources were to be at the disposal of the government. The effort was directed by a Production Executive, coordinating the efforts of the supply ministries, and setting priorities. The National Service Act at the end of 1941 conscripted all men aged 18–50 and women aged 20–30 (later also raised to 50) for military or labour purposes. Labour was directed by the Production Executive and by Bevin’s Ministry. Given Britain’s dependence on imports, strict controls over consumption in the form of rationing, and measures to boost agricultural output, such as the ‘Dig for Victory’ campaign, were vital as the U-boats took an increasing toll in the Atlantic. Britain still came within six weeks of running out of food in late 1942.

Churchill gave himself a unique position at the centre of Britain’s war effort, naming himself Minister of Defence as well as Prime Minister. He chaired the Defence Committee and was able to indulge his passion for military and naval matters, sometimes to the despair of the professionals like General Brooke, the Chief of the Imperial General Staff from the end of 1941. This did mean, however, that Churchill was able to infuse his government with his own energy and determination. By no means all his strategic decisions were good ones, and in the years of setbacks between 1940 and 1942 he suffered much criticism, especially within the Conservative Party, which only reluctantly accepted him as its leader. For the British public, however, and for world opinion (most importantly, American), Churchill personified the British fighting spirit.

Britain ended the war exhausted. Rationing had been extensive and Britain’s assets had been liquidated before the advent of Lend-Lease. Destruction by bombing would take years to make good, as Britain entered the post-war period with the intention of continuing to play the world role its status as victor implied. This included regaining control of its empire, an exercise that would prove costly and ultimately futile. For the British population, faced in the future with the uncertainties that these issues presented, the war was to represent a defining moment: particularly the year when Britain stood virtually alone, and Dunkirk and the Blitz formed a potent mythology of a Britain united. In fact, while the war did not throw up internal conflict as in some other belligerents, it generated a determination for reform and a rejection of the past (especially the Depression years) that produced a sweeping Labour victory in the election of June 1945, and the removal from office of Churchill at his moment of victory – an event that caused astonishment elsewhere in the world, but was reflective of the underlying social change, even discontent, that the war fostered in Britain.