1918: Beginning of the Austrian-Yugoslav border conflict

The border between Carinthia and the Kingdom of Slovenes, Croats and Serbs (SHS) was contested until October 10, 1920. The provisional state assembly of Carinthia had decided to join the Republic of German Austria, but on November 5, 1918, SHS troops penetrated the borders in order to claim the mixed-language territory for itself. On December 5, 1918, the Carinthian provincial government voted for armed resistance, which the young republic could only informally support, since it needed food supplies from the SHS Kingdom. In January 1919 it came to a ceasefire and a US mission - the so-called Miles Mission - visited. The Miles Mission ultimatley achieved that the Treaty of Saint Germain provided for a plebiscite in South Carinthia.

Fighting continued, however. For the time being, the Carinthians succeeded at reconquering the occupied territories, but in June 1919, Klagenfurt was occupied and, only on orders from Paris, was it evacuated. There were over 200 deaths.

The plebiscite that was held on October 19, 1920 in the southern Zone A resulted in 59% of voters choosing to remain in Austria. Every second resident whose mother tongue was Slovenian voted for Austria as well.