The primary outcome of the Treaty of Trianon, signed in 1920, was the significant territorial loss for Hungary after World War I. The treaty marked the dissolution of the Austro-Hungarian Empire, significantly reducing Hungary's territory by about two-thirds and population by millions. Hungary lost territories to neighboring countries, including Romania, Czechoslovakia, and Yugoslavia, which led to lasting ethnic tensions and national grievances among Hungarians. The treaty reshaped Central European geopolitics and contributed to Hungary's sense of national trauma, impacting its interwar politics and fostering revanchism that influenced future regional conflicts.