History of the First World War: Causes and Impact The First World War, which lasted from 1914 to 1918, was one of the largest and most destructive conflicts in human history. The causes are very complex, involving various political, economic and social factors that developed in Europe at the beginning of the 20th century. One of the main causes is a complicated alliance system. Two main blocs were formed: the Allies (including Britain, France, and Russia) and the Central Powers (including Germany, Austria-Hungary, and the Ottoman Empire). Tensions between these countries are increasing as the arms race and nationalism become increasingly prominent. The event that sparked the war was the assassination of Archduke Franz Ferdinand in Sarajevo on 28 June 1914, which caused Austria-Hungary to issue an ultimatum against Serbia. The conflict quickly spread as the countries involved in the alliance dragged each other down. Rapid military mobilization worsened the situation, and soon war engulfed Europe. Fierce fighting took place on various fronts, including on the Western Front, famous for the battles at Verdun and the Somme. The impact of the First World War was enormous and far-reaching. In human terms, more than 16 million people died, with millions more injured. In addition to the human impact, this war also resulted in the collapse of great empires such as the Austro-Hungarian and Ottoman ones, replacing them with new states in Europe and the Middle East. Economically, the war drained the country’s resources, damaged infrastructure, and caused a prolonged recession. The Allied nations, despite their victory, had to face debt problems and post-war economic adjustments. On the other hand, several countries such as the United States are emerging as new economic powers. Society and culture were also affected by the war. The massive loss in human life and the trauma experienced by soldiers and civilians changed the world view. Artists and writers began to create works that reflected their disappointment and sadness, resulting in a new generation of literature and art. In addition, political changes occurred, giving rise to new ideologies such as communism after the Russian Revolution of 1917, which was fueled by dissatisfaction with the government. And in the end, the Treaty of Versailles signed in 1919 attempted to establish peace, but instead created feelings of resentment in Germany, which would later contribute to the emergence of the Second World War. The causes and impact of the First World War are a reflection of the complex dynamics between nations, as well as the profound impact that shaped world history for the following decades. This war not only changed the political map of Europe, but also provided important lessons about the consequences of unaddressed tensions.