The Treaty of Trianon, signed in 1920, had a profound impact on Hungary, significantly altering its borders and reducing its territory by about two-thirds. The treaty emerged from the aftermath of World War I and aimed to dismantle the Austro-Hungarian Empire. Hungary lost significant land to neighboring countries, including Romania, Czechoslovakia, and Yugoslavia, which led to deep national trauma and a sense of grievance. These territorial losses diminished Hungary’s population and resources, fostering feelings of vulnerability and irredentism that would influence Hungarian politics and nationalism in the interwar period and beyond, including the rise of revisionist ideologies.