Breakup of Hungary 1945 - Hungary emerged devastated from the First World War. The Austro-Hungarian Empire collapsed in 1918 and Hungary was compelled to sign the Treaty of Trianon by which she lost two-thirds of her historic territory, one-third of her Magyar population and two thirds of her total population. It was the greatest blow suffered by Hungary since her defeat by the Turks in 1526.
History of Hungary.the Treaty of Trianon: Hungary lost of its land and sea ports in Croatia, Magyars found themselves seperated from their motherland. the country lost 5 of its 10 biggest Hungarian cities.