Which major event prompted the collapse of several empires during the 20th century?

The collapse of several empires during the 20th century was significantly influenced by World War I. The war, which lasted from 1914 to 1918, caused widespread destruction and led to profound political changes in Europe and beyond. Major empires, such as the Austro-Hungarian, Ottoman, Russian, and German empires, experienced significant destabilization as a result of the war.

Firstly, the war heightened nationalist sentiments within various regions of these empires, as ethnic groups sought self-determination and political autonomy. The defeat of these empires in the war led to the signing of treaties, such as the Treaty of Versailles, which dismantled imperial structures and redrew national boundaries, often without regard to ethnic or cultural considerations, leading to further instability.

Secondly, the enormous human and economic costs of the war drained resources and weakened the political will of imperial governments. Social unrest grew as people demanded changes and reforms, contributing to revolutions in countries like Russia, which resulted in the Bolshevik Revolution and the establishment of the Soviet Union.

Overall, World War I was a pivotal event that not only marked the end of several longstanding empires but also set the stage for future conflicts and the reshaping of global politics.