Austria–Yugoslavia relations were historical foreign relations between Austria and now broken up Yugoslavia. Both countries were created following the dissolution of Austria-Hungary in 1918. First Austrian Republic was a successor state of the empire while Yugoslavia was created after the unification of pre-World War I Kingdom of Serbia with the State of Slovenes, Croats and Serbs (former South Slavic parts of the Austria-Hungary). In the days before this unification Kingdom of Serbia merged with the Banat, Bačka and Baranja and the Kingdom of Montenegro. During the interwar period of European history relations between the First Austrian Republic and the Kingdom of Yugoslavia were marked by the Austro-Slovene conflict in Carinthia, 1920 Carinthian plebiscite, 1920 establishment of pro-stat