A part of the Habsburg Monarchy until the First World War, most of Slovenia joined the Kingdom of Serbs, Croats and Slovenes in 1918, thus becoming a part of Yugoslavia in 1929. A sliver of Slovenia’s coastal region, however, was awarded to Italy in 1920. In April 1941, when Germany’s twelve-day campaign against Yugoslavia led to its partition between the Axis powers and her allies, southern Slovenia and Ljubljana were annexed by Italy, while Germany occupied northern and eastern Slovenia (the Slovenian Styria, Upper Carniola, Slovenian Carinthia, and Posavje regions) and attached these areas to Carinthia and Steiermark Reichsgaue. Hungary occupied the Prekmurje region, and some villages in Lower Carniola were annexed by the newly-founded Independent State of Croatia (Nezavisna Država Hrvatska, NDH). When Italy concluded a separate peace with the Allies in September 1943, Germany took over its part of occupied Slovenia. In May 1945, Slovenia became a part of Yugoslavia again. In June 1991, Slovenia declared independence.
On the eve of the Second World War, Slovenia had an estimated overall population of 1,450,000 people. According to official Yugoslav data, there were 1,533 adherents of the Jewish religion in Slovenia in 1939, most of them in the Prekmurje region. Prior to the Axis invasion of Yugoslavia, that number jumped to around 2,500 due to an influx of refugees from Germany and Austria, including baptised Jews. After April 1941, the German occupiers introduced Nazi racial and purification policies. In Italian-occupied Ljubljana and Lower Carniola, the Jews enjoyed relative safety until these regions were taken over by the Germans in September 1943. By the end of 1943, many Jews had been deported to concentration camps, but some did manage to escape to partisan-controlled areas. When the previously Hungarian-occupied Prekmurje region – where most Slovenian Jews had lived before the outbreak of the Second World War – also fell under German control in the spring of 1944, nearly all the Jews in the area were deported to Auschwitz. Only a handful survived.
On 31 October 1945, the National Government of Slovenia established the Central State Archives of Slovenia, which in 1991 was renamed the Archives of the Republic of Slovenia. The Historical Archives of the Central Committee of the League of Communists of Slovenia merged with the national archives in 1990, while the former Archives of the Institute of the History of the Labour Movement (later renamed the Institute of Contemporary History) were included in 1992. In 1998, part of the Archives of the Ministry of Internal Affairs, which kept records of the National Security Agency, was also included. Apart from the main repository in the Gruber Palace in the capital Ljubljana, the Archives of the Republic of Slovenia have six other branches: Four in Ljubljana, and one in Gotenica and Borovec in the Kočevje region. In addition to these national archives, Slovenia has regional, church, and university archives.
EHRI has identified the Archives of the Republic of Slovenia, the National Museum of Contemporary History, and two smaller regional institutions – Center of Jewish Cultural Heritage Synagogue Maribor and the National Liberation Museum Maribor – as organisations that are likely to hold Holocaust-relevant sources, but it is yet to determine the exact number and importance of their collections. Outside of Slovenia, the Croatian State Archives in Zagreb and Rijeka hold significant collections that are relevant to Holocaust research on Slovenia. Furthermore, the United States Holocaust Memorial Museum has collected a number of oral history interviews on Slovenia during the Holocaust period, and is in possession of the Eventov Archive of the Association of Immigrants from the former Yugoslavia in Israel.