World War I, which lasted from 1914 to 1918, was one of the most significant conflicts in world history. The causes of this conflict are complex and varied, including interrelated political, economic and social factors. Among the main causes are overflowing nationalism, imperialism, and alliances that form mutual power blocs. Extreme nationalism in various European countries, especially in the Balkan region, created serious tensions between major powers. Dissatisfaction and desire for independence in the area sparked conflict between the Austro-Hungarian Empire and Serbia, following the assassination of Archduke Franz Ferdinand in 1914. This case was the spark that lit the flames of war. This war was also triggered by imperialistic competition. European countries competed to expand their colonial territories, creating tensions in Africa and Asia. As the rise of German power challenged the status quo of great powers such as Britain and France, tensions increased. A complex alliance system also contributed to the outbreak of war. Two power blocs, namely the Allies (including Britain, France, and Russia) and the Central Empire (including Germany, Austria-Hungary, and the Ottomans), were bound together in an agreement that caused local conflicts to quickly escalate into global war. The impact of World War I was enormous and ongoing. Politically, the war led to the collapse of several empires, including the Ottoman and Austro-Hungarian Empires, and the emergence of new states in Europe. Treaties such as the Treaty of Versailles produced temporary peace, but also planted the seeds of future conflict. Socially, war brings major changes in the structure of society. Many countries experienced demographic changes, with millions of soldiers and civilians losing their lives. Women’s roles also changed, as they entered the workforce to replace men who had gone to war, paving the way for the women’s rights movement. The world economy was also badly affected, with many countries experiencing post-war inflation and poverty. The concessions given to the countries concerned added to the economic and social burden experienced by Europe. World War I also changed the political and geographical map of the world. New ideologies such as communism emerged from the resulting chaos, changing the course of history in many countries. This war provided an important lesson for future peace planning and international diplomacy, establishing institutions such as the League of Nations, although it failed to prevent further conflict. The end of this conflict created a deep chasm between winners and losers, fueling anger and a desire for revenge that would culminate in World War II. Overall, World War I was a turning point that redefined political, social, and economic boundaries throughout the world.