The End of Empire: Breakup of the Austria-Hungarian Empire 1919–20

The carve-up of the territories of the defunct Austro-Hungarian Empire was not an orderly process. In the south, the Kingdom of Serbs, Croats and Slovenes (KSCS) was proclaimed but remained in dispute with Italy until the Treaty of Rapallo in 1920. In February 1919, the Allied council, then negotiating the Treaty of Versailles, authorized the transfer of western portions of the kingdom of Hungary to Romania. Hungary refused and war ensued ending with the Romanian occupation of Bucharest. In the 1920 Treaty of Trianon, the kingdom of Hungary was forced to cede over 70 per cent of its pre-war territories to Romania, KSCS and Czechoslovakia respectively. Over 30 per cent of ethnic Hungarians were now living outside the kingdom. The much-reduced kingdom of Austria was confirmed by the Treaty of St Germain en Laye in September 1919; the provisions of the Treaty effectively demilitarized the country and prohibited its union with Germany.