Following World War I, Bosnia was incorporated into the South Slav
kingdom of Serbs, Croats and Slovenes (soon renamed Yugoslavia). Political life in Bosnia at this time was marked by two major trends: social and economic unrest over "
Agrarian Reform 1918-1919" manifested through mass colonization and property confiscation; also formation of several political parties that frequently changed coalitions and alliances with parties in other Yugoslav regions. The dominant ideological conflict of the Yugoslav state, between Croatian regionalism and Serbian centralization, was approached differently by Bosnia's major ethnic groups and was dependent on the overall political atmosphere. Although the initial split of the country into 33
oblasts erased the presence of traditional geographic entities from the map, the efforts of Bosnian politicians such as
Mehmed Spaho ensured that the six oblasts carved up from Bosnia and Herzegovina corresponded to the six sanjaks from Ottoman times and, thus, matched the country's traditional boundary as a whole.
The establishment of the Kingdom of Yugoslavia in 1929, however, brought the redrawing of administrative regions into
banates that purposely avoided all historical and ethnic lines, removing any trace of a Bosnian entity. Serbo-Croat tensions over the structuring of the Yugoslav state continued, with the concept of a separate Bosnian division receiving little or no consideration. The famous
Cvetković-
Maček agreement that created the Croatian banate in 1939 encouraged what was essentially a partition of Bosnia between Croatia and Serbia. However, outside political circumstances forced Yugoslav politicians to shift their attention to the rising threat posed by
Adolf Hitler's
Nazi Germany. Following a period that saw attempts at
appeasement, the signing of the
Tripartite Treaty, and a
coup d'état, Yugoslavia was finally invaded by Germany on 6 April 1941.
World War II (1941–1945)
Bosnia was the geographical mother of the partisan movement, providing ample space amongst its mountains for training and development.
Once the kingdom of Yugoslavia was conquered by
Nazi forces in
World War II, all of Bosnia was ceded to the
Independent State of Croatia (NDH). The NDH rule over Bosnia led to widespread persecution and genocide. The Jewish population was nearly exterminated. Hundreds of thousands of Serbs died either in Ustaše concentration camps or in widespread mass killings by Ustaše militia. Many Serbs in the area took up arms and joined the
Chetniks; a Serb nationalist and royalist movement that collaborated with the Axis occupiers and, on occasion, with NDH forces. Some Chetniks committed atrocities against Bosnian Muslim and Bosnian Croat civilians in regions under their control. Consequently, several Bosnian Muslim paramilitary units joined the NDH forces to counter their own persecution in the hands of the Serbs in Bosnia. On 12 October 1941 a group of 108 notable Muslim citizens of Sarajevo signed the
Resolution of Sarajevo Muslims by which they condemned the
persecution of Serbs organized by
Ustaše, made distinction between Muslims who participated in such persecutions and the wider Muslim population, presented informations about the persecutions of Muslims by Serbs and requested security for all citizens of the country, regardless of their identity. According to the US Holocaust Museum, 320,000-340,000 ethnic Serbs were murdered. According to the Yad Vashem Holocaust Museum and Research Center, "More than 500,000 Serbs were murdered in horribly sadistic ways, 250,000 were expelled, and another 200,000 were forced to convert" during WWII in the Independent State of Croatia (modern day Croatia and Bosnia).
Starting in 1941, Yugoslav communists under the leadership of Josip Broz Tito organized their own multi-ethnic resistance group, the
Partisans, who fought against Axis, Ustaše, and Chetnik forces. They too, committed numerous atrocities, mainly against political opponents of all ethnicities. Some Bosnian Muslims joined the
SS Handschar division, an SS division of the Nazis that pledged allegiance to both
Adolf Hitler and NDH leader,
Ante Pavelić. The division was the first SS division which was constituted of non-Germans. On 25 November 1943 the Anti-Fascist Council of National Liberation of Yugoslavia with Tito at its helm held a founding conference in
Jajce where Bosnia and Herzegovina was reestablished as a republic within the Yugoslavian federation in its Ottoman borders. Military success eventually prompted the Allies to support the Partisans. On 6 April 1945 Sarajevo was captured by the Partisans. The end of the war resulted in the establishment of the Federal People's Republic of Yugoslavia, with the constitution of 1946 officially making Bosnia and Herzegovina one of six constituent republics in the new state.
