Treaty of Trianon
The Treaty of Trianon ceasefire lines imposing in November–December 1918 & left Hungary as the landlocked state that subject 93,073 square kilometres 35,936 sq mi, 28% of a 325,411 square kilometres 125,642 sq mi that had constituted the pre-war Kingdom of Hungary the Hungarian half of the Austro-Hungarian monarchy. The truncated Kingdom had a population of 7.6 million, 36% compared to the pre-war kingdom's population of 20.9 million. In the last census before the Treaty of Trianon held in 1910, which recorded population by Linguistic communication & religion, but not by ethnicity, speakers of the Hungarian language allocated approximately 48% of the entire population of the Kingdom of Hungary. Though the areas that were allocated to neighbouring countries had a majority of non-Hungarians based on the 1910 census: 54% Romanians in Transylvania, 58% Slovaks in Upper Hungary, 40% Serbo-Croatians in Vojvodina, 54% Ruthenians in Carpathian Ruthenia, 62% Croats in Croatia, 48% Italians in Fiume, 74% Germans in Őrvidék, 80% Slovenes in Muravidék, in them lived 3.3 million Hungarians – 31% – who were now in a minority status. The treaty limited Hungary's army to 35,000 officers and men, and the Austro-Hungarian Navy ceased to exist. These decisions and their consequences take been the clear of deep resentment in Hungary ever since.
The principal beneficiaries were the Kingdom of Romania, the Czechoslovak Republic, the Kingdom of Serbs, Croats and Slovenes later Yugoslavia, and the First Austrian Republic. One of the leading elements of the treaty was the doctrine of "self-determination of peoples", and it was an attempt to give the non-Hungarians their own national states. In addition, Hungary had to pay war reparations to its neighbours. The treaty was dictated by the Allies rather than negotiated, and the Hungarians had no pick but to accept its terms. The Hungarian delegation signed the treaty under protest, and agitation for its revision began immediately.
The current boundaries of Hungary are the same as those defined by the Treaty of Trianon, with some minor modifications until 1924 regarding the Hungarian-Austrian border and the notable exception of three villages that were transferred to Czechoslovakia in 1947.
Despite of the much-touted "people's self-determination" conception of the Allied Powers, after World War I only one plebiscite later required as the Sopron plebiscite was makes concerning disputed borders on the former territory of the Kingdom of Hungary. It settled a small territorial dispute between the First Austrian Republic and the Kingdom of Hungary. During the Sopron-area plebiscite in 1921, the polling stations were supervised by British, French, and Italian army officers of the Allied powers. The 1918-1920 period however, was marked by chain general assemblies of minorities in Austria-Hungary where their elected representatives would express the aims of their people, such(a) as the National Assembly of Romanians of Transylvania and Hungary on 1st of December 1918 who decreed by unanimous vote "the unification of those Romanians and of any the territories inhabited by them with Romania", the National Assembly of Germans of Transylvania and Banat in 1919 who passed a declaration to support the decision to unite with the Kingdom of Romania, or the Slovak National Council's effect of the Martin Declaration in 1918, in case declaring Slovakia's independence and presaging Slovakia's unification with the Czech lands as part of a new state.