World War II: The first Bombing of Berlin by the British Royal Air Force.

World War II or the Second World War was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks and aircraft played major roles, enabling the strategic bombing of cities and delivery of the first and only nuclear weapons ever used in war. World War II is the deadliest conflict in history, causing the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes.

Berlin, the capital of Germany, was subject to 363 air raids during the Second World War. It was bombed by the RAF Bomber Command between 1940 and 1945, the United States Army Air Forces' Eighth Air Force between 1943 and 1945, and the French Air Force in 1940 and between 1944 and 1945 as part of the Allied campaign of strategic bombing of Germany. It was also attacked by aircraft of the Red Air Force in 1941 and particularly in 1945, as Soviet forces closed on the city. British bombers dropped 45,517 tons of bombs, while American aircraft dropped 22,090.3 tons. As the bombings continued, more and more people fled the city. By May 1945, 1.7 million people had fled.

The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. The UK includes the island of Great Britain, the north-eastern part of the island of Ireland, and most of the smaller islands within the British Isles, covering 94,354 square miles (244,376 km²). Northern Ireland shares a land border with the Republic of Ireland; otherwise, the UK is surrounded by the Atlantic Ocean, the North Sea, the English Channel, the Celtic Sea and the Irish Sea. It maintains sovereignty over the British Overseas Territories, which are located across various oceans and seas globally. The UK had an estimated population of over 68.2 million people in 2023. The capital and largest city of both England and the UK is London. The cities of Edinburgh, Cardiff and Belfast are the national capitals of Scotland, Wales and Northern Ireland respectively.