of Hungary until 1848 when it was transferred back to Buda. During the revolution of 1848–49, the Slovaks supported the Austrian Emperor, hoping for independence from the Hungarian part of the Dual Monarchy, but they failed to achieve their aim. Thereafter relations between the nationalities deteriorated (see Magyarisation), culminating in the secession of Slovakia from Hungary after World War I. Czechoslovakia (1918–1939) On 18 October 1918, Tomáš Garrigue Masaryk, Milan Rastislav Štefánik and Edvard Beneš declared in Washington, D.C. the independence for the territories of Bohemia, Moravia, Silesia, Upper Hungary and Carpathian Ruthenia from the Austro-Hungarian Empire and proclaimed a common state, Czechoslovakia. In 1919, during the chaos following the break-up of Austria-Hungary, Czechoslovakia was formed with numerous Germans, Slovaks, Hungarians and Ruthenians within the newly set borders. The borders were set by the Treaty of Saint Germain and Treaty of Trianon. In the peace following the World War, Czechoslovakia emerged as a sovereign European state. It provided what were at the time rather extensive rights to its minorities. During the Interwar period, democratic Czechoslovakia was allied with France, and also with Romania and Yugoslavia (Little Entente); however, the Locarno Treaties of 1925 left East European security open. Both Czechs and Slovaks enjoyed a period of relative prosperity. There was progress in not only the development of the country's economy but also culture and educational opportunities. Yet the Great Depression caused a sharp economic downturn, followed by political disruption and insecurity in Europe. In the 1930s Czechoslovakia came under continuous pressure from the revisionist governments of Germany, Hungary and Poland who used the aggrieved minorities in the country as a useful vehicle. Revision of the borders was called for, as Czechs constituted only 43% of the population. Eventually, this pressure led to the Munich Agreement of September 1938, which allowed the majority ethnic Germans in the Sudetenland, borderlands of Czechoslovakia, to join with Germany. The remaining minorities stepped up their pressures for autonomy and the State became federalised, with Diets in Slovakia and Ruthenia. The remainder of Czechoslovakia was renamed Czecho-Slovakia and promised a greater degree of Slovak political autonomy. This, however, failed to materialise. Parts of southern and eastern Slovakia were also reclaimed by Hungary at the First Vienna Award of November 1938. World War II (1939–1945) After the Munich Agreement and its Vienna Award, Nazi Germany threatened to annex part of Slovakia and allow the remaining regions to