The historical event associated with the rise of totalitarian regimes in Europe during the 20th century is World War I and its aftermath. The war resulted in significant social, political, and economic upheaval across Europe. The Treaty of Versailles in 1919 imposed heavy reparations on Germany, leading to economic hardship and widespread discontent. This environment fueled extremist ideologies, such as fascism and communism, allowing leaders like Adolf Hitler in Germany and Benito Mussolini in Italy to rise to power. These totalitarian regimes suppressed dissent, controlled economies, and pursued aggressive expansionist policies, leading to catastrophic consequences, including World War II.