We cannot speak of Hungarian minorities in the Carpathian Basin until 1920, the year of the peace treaty of Trianon, the partitioning of the historical territory of Hungary. The detached areas constituted an organic part of Hungary from the 10th century up to 1920. During the past seven decades this dismembered situation determined their destiny and their statistical number registered by the Czechoslovak, Rumanian, Yugoslav etc. After 1920 these areas became massively militarized frontier zones at the periphery of the neighboring countries. 350,000 Hungarians fled to the new Hungarian territory in the period between 1918-1924.
Ethnical status is a very subjective social structural element.
It relies on the personal beliefs of the individual, and is much influenced by the prevailing ideological and political system. Between the two wars the most striking phenomenon in this respect was that Jews and Gypsies were listed in different categories in Czechoslovakia and Rumania. This diminished the number of those people who considered themselves Hungarians mostly in Transcarpathia, Slovakia and Transylvania as compared to the statistic reports in 1910. The above presented phenomena led to the diminishing of Hungarians mostly in Transylvania and Slovakia, and to some extent in Croatia, Burgenland and Transcarpathia. Besides the emigrations and the casualties during the war, then the annihilation of the Jewish Hungarians - the statistic number of Hungarians in the neighboring countries was mostly diminished by the fact that those groups, whose awareness of nationality was not very strong and as a consequence, was always vacillating, now declared themselves to belong to the majority population.