In the Great War (1914-1918), Hungary, as part of the Austro-Hungarian Empire, took part on the side of the Central Powers, as an ally of Germany and Turkey. The opposing Entente Powers included Britain, France and the Russian Empire. After the failure of the “lightning war” strategy, which both sides had taken for granted, the war settled into trench warfare for the first time in history. Hungary participated in the Great War beyond its means, its military-economic weight: between 1914 and 1918 more than 3 million soldiers served in the Serbian, Galician and Romanian fronts, as well along the Isonzo River. By the autumn of 1918, the economies of the Central Powers could no longer keep pace with the Entente’s war machine, and after the decisive military defeats suffered in October, both the Hungarian army and Austria-Hungary began to disintegrate. The armistice agreement was signed in Padua on 3 November by an Austro-Hungarian Monarchy that no longer existed in fact.

At the end of the Great War, Hungary stepped into a period of confusion and chaos in domestic politics that lasted for almost two years, ending with the consolidation of the Horthy regime. The last and most serious consequence of Hungary’s defeat in the Great War defeat was the peace treaty signed on 4 June 1920 in the Grand Trianon Castle of the Royal Palace of Versailles, which made the dissolution of the historical Hungary official.