The Austrian Wars were a series of geopolitical conflicts that occurred starting with the 1949 Partition of Austria, in which the old Austrian Empire split into the sovereign nations of the Kingdom of Austria and Kingdom of Hungary, which previously had shared a single ruler, and the ensuing nationalist coup d'etat in Hungary which toppled the short-lived monarchy there. The Austrian Wars resulted in the splintering of the old Austrian Empire, which had been federalized in 1917 under Franz Ferdinand. While states such as Bohemia and East and West Galicia quickly separated from the new Austrian borders without much violence, there was much bloodshed in Hungary, which immediately defederalized in the fall of 1949 after the Szalasi coup that summer and began a campaign of "Magyarization," in particular in Slovakia and Croatia.
Slovakia began an armed rebellion against the Szalasi regime, including the assassination of Szalasi in 1951, which triggered widespread unrest as Rumania launched an invasion of Transylvania and Czechoslovakia, the old Bohemia, attempted to complete its annexation of Slovakia. In 1952, the Republic of Galicia - formed in 1949 out of the two old states - voted to join the Ukraine, causing an armed uprising amongst the Polish population that eventually started the Galician War between Poland, backed by Germany, and the Ukraine, backed by Britain and Hungary. In addition, Croatia began the Croatian War of Independence later in 1952 to devolve from Austria, which they eventually won, while the Carniolan Rebellion in southern Austria was stamped out by 1954.
The Austrian Wars became a major focal point of the early Cold War, with Austria and its client states receiving the support of Germany and its fellow powers while Hungary, which had a Communist-sympathetic strongman in Istvan Dobi, who while not a Communist himself supported a leftist Magyar nationalism and emerged as the main power in Hungary following the chaos brought on by Szalasi's assassination.