The main cause of World War I, also known as the First World War, was a complex combination of factors, including political alliances, territorial disputes, militarism, and nationalism. The immediate trigger was the assassination of Archduke Franz Ferdinand of Austria-Hungary by a Serbian nationalist in June 1914, which led to a cascading chain of events and the declaration of war. However, the underlying causes of tension and rivalry among major powers in Europe, especially between the alliance systems of the Triple Entente (comprised of France, Russia, and Britain) and the Central Powers (comprised of Germany, Austria-Hungary, and later joined by the Ottoman Empire), played a significant role in escalating the conflict into a global war.
