A world war is an international conflict that involves most or all of the world 's major powers. Learn about the etymology, history and examples of world wars, such as World War I and World War II, and their consequences and controversies. World War I, commonly referred to as the Great War, was a devastating worldwide conflict that engulfed the world from 1914 to 1918, sparked by the assassination of Archduke Franz Ferdinand of Austria. World War I, also known as the Great War, started in 1914 after the assassination of Archduke Franz Ferdinand of Austria. His murder catapulted into a war across Europe that lasted until 1918. Introduction to World War II (1939–1945) World War II (1939–1945) was the deadliest, most costly, most widespread war in human history. The war saw the decline of the European colonial powers that had dominated global politics for the previous four centuries and the rise of the United States and the Soviet Union as superpowers. Tremendous advances in science, medicine, and military technology were made over the course of the conflict—from antibiotics to the atomic bomb —and ...
