The Second World War was a global military conflict that took place from 1939 to 1945. It involved the majority of the world's nations, divided into two opposing alliances: the Allies and the Axis powers. Sparked by the aggressive expansionist policies of Nazi Germany under Adolf Hitler, the war originated in Europe but quickly spread across the globe, engulfing nations in Asia, Africa, and the Pacific.
The war saw the deployment of new military technologies and tactics, such as aerial bombings, armored warfare, and the use of nuclear weapons, which led to unparalleled destruction and loss of life. Major theatres of war included Europe, the Pacific, Africa, and the Atlantic, with battles fought on land, at sea, and in the air. Notable campaigns and conflicts included the Battle of Britain, the Normandy landings, the Battle of Stalingrad, the Holocaust, the Pacific island-hopping campaigns, and the atomic bombings of Hiroshima and Nagasaki.
The war ended in 1945 with the unconditional surrender of the Axis powers. The conflict resulted in the death of approximately 70-85 million people, making it the deadliest in human history. It also led to the establishment of the United Nations and redefined the global power dynamics, with the emergence of two superpowers, the United States and the Soviet Union. The Second World War remains a pivotal event in history that continues to shape geopolitical relationships, international institutions, and the memory of the modern world.
