The 20th century

Optimism and reform

In the early 1900s Britain was a global 'superpower' with a vast Empire, admired navy and strong industry. Social reforms included help for the unemployed, old-age pensions and free school meals, safer workplaces, stricter town planning to stop slums, better support for mothers and children after separation, more democratic local government, and — for the first time — a salary for MPs.

The First World War (1914–18)

The assassination of Archduke Franz Ferdinand of Austria on 28 June 1914 triggered the war, though nationalism, militarism, imperialism and rival alliances had prepared the ground. Britain fought with the Allied Powers — including France, Russia, Japan, Belgium and Serbia, later joined by Greece, Italy, Romania and the USA — against the Central Powers: mainly Germany, Austria-Hungary, the Ottoman Empire and later Bulgaria.

The whole Empire took part: more than a million Indians fought for Britain (about 40,000 died), as did men from the West Indies, Africa, Australia, New Zealand and Canada. Britain suffered more than 2 million casualties. On the first day of the Somme offensive in July 1916 alone there were about 60,000 British casualties. The war ended at 11 am on 11 November 1918 with victory for Britain and its allies.

The partition of Ireland

In 1913 the government promised Irish Home Rule, but Protestants in the north threatened to resist by force, and the war postponed it. In 1916 nationalists staged the Easter Rising in Dublin; its leaders were executed and a guerrilla war followed. A peace treaty in 1921 led in 1922 to two countries: six mainly Protestant northern counties stayed in the UK as Northern Ireland, and the rest became the Irish Free State, a republic from 1949. Disagreement over the split later fed a terror campaign known as 'the Troubles'.

Exam tip: peace treaty 1921, Ireland becomes two countries 1922, the Irish Free State becomes a republic 1949. Northern Ireland is six counties.

Between the wars

Housing improved in the 1920s, but in 1929 the Great Depression hit. Shipbuilding and other heavy industries suffered mass unemployment, while new car and aircraft industries grew; with falling prices, people in work were better off, and car ownership doubled from 1 to 2 million between 1930 and 1939. Culture flourished — writers Graham Greene and Evelyn Waugh, economist John Maynard Keynes. The BBC began radio in 1922 and the world's first regular television service in 1936.

The Second World War (1939–45)

Hitler took power in Germany in 1933, rebuilt its armed forces and seized Austria and Czechoslovakia. When he invaded Poland in 1939, Britain and France declared war. The Axis powers were Germany, Italy and Japan; the main Allies were the UK, France, Poland, Australia, New Zealand, Canada and South Africa. In 1940 Germany overran Belgium, the Netherlands and France, and Winston Churchill became Prime Minister.

Churchill, a former soldier and journalist and a Conservative MP, refused to surrender and inspired the nation. He lost the 1945 election, returned as PM in 1951, received a state funeral in 1965 and in 2002 was voted the greatest Briton of all time. His speeches include 'blood, toil, tears and sweat', 'we shall fight on the beaches' and, about the RAF pilots, 'never … was so much owed by so many to so few'.

As France fell, the Navy and civilian volunteers in small boats rescued over 300,000 troops from Dunkirk — the origin of 'the Dunkirk spirit'. From June 1940 to June 1941 Britain and the Empire stood almost alone. In the summer of 1940 the RAF, flying Spitfires and Hurricanes, won the Battle of Britain, stopping a German invasion. Germany then bombed cities by night in the Blitz: Coventry was almost destroyed and London's East End badly hit, giving us 'the Blitz spirit'.

Japan defeated the British in Singapore and occupied Burma. The USA joined after Japan attacked Pearl Harbour in December 1941, the same year Hitler invaded the Soviet Union. After Allied victories in North Africa and Italy, troops landed in Normandy on D-Day, 6 June 1944, and Germany was defeated in May 1945. The war with Japan ended in August 1945 when the USA dropped atomic bombs on Hiroshima and Nagasaki. Scientists led by Ernest Rutherford, at Manchester and then Cambridge, had been the first to 'split the atom', and British scientists took part in the Manhattan Project that developed the bomb.

Alexander Fleming, born in Scotland, discovered penicillin in 1928 while researching flu. Howard Florey and Ernst Chain turned it into a usable drug, mass-produced by the 1940s, and Fleming won the Nobel Prize in Medicine in 1945.

Exam tip: Dunkirk (evacuation by sea) and the Battle of Britain (in the air) were both 1940. The Blitz was night bombing of cities. D-Day was 6 June 1944 in Normandy, France.