The European powers had been competing for colonies and influence in Africa, Asia, and the Middle East for decades. This competition led to a number of conflicts, including the First and Second Moroccan Crises, the Russo-Japanese War, and the Italo-Turkish War.
By 1914, the European powers were divided into two rival alliances: the Triple Entente (Britain, France, and Russia) and the Central Powers (Germany, Austria-Hungary, and Italy). The assassination of Archduke Franz Ferdinand of Austria in June 1914 sparked a chain of events that led to the outbreak of World War I.
Territorial expansion was a key factor in the start of World War I because it created rivalries between the European powers and increased tensions between them. The war itself was fought over territorial disputes, such as the control of Alsace-Lorraine, which had been annexed by Germany from France in 1871.
The Treaty of Versailles, which ended World War I, redrew the map of Europe and created several new countries. This territorial settlement was resented by many Germans, who felt that they had been treated unfairly. The desire to regain lost territory was a major factor in the rise of Adolf Hitler and the Nazi Party in Germany.