A heterogeneous state whose only period of stability (1945–80) was achieved through political repression.

Statehood and early tensions (1918–45)

A state created on 1 December 1918 as the Kingdom of Serbs, Croats, and Slovenes. It emerged from the Corfu Pact of 1917, and was a heterogeneous country consisting of Slovenia, Croatia, Bosnia‐Hercegovina, Serbia, and Montenegro. The new country's religious and ethnic diversity was expressed in two mutually contrasting ideas about the nature of the new state. Slovenia and Croatia had joined the union with Serbia largely for defensive reasons, to protect their territories against Austrian or Italian revisionist (irredentist) pretensions. They demanded a federal state, which would leave each component with extensive autonomy. By contrast, Serbia was a relatively homogeneous country which had gained increasing self‐confidence since independence in 1878, so that it was interested mainly in increasing its power over other territories in a ‘Greater Serbia’.

This latter conception won the day, when a centralized constitution was adopted by a narrow parliamentary majority in 1921. In protest, the Croatian People's Peasants' Party (CPPP) as well as other groups made parliament extremely unstable. After the assassination of the CPPP leader, Stjepan Radić, in 1928, King Alexander I dissolved parliament and created a royal dictatorship, changing the country's name to Yugoslavia (‘Land of Southern Slavs’). His rule strengthened Serbian predominance even further, which motivated the growth of a number of terrorist movements, the most important of which became the Ustase movement, which carried out Alexander's assassination in 1934.

Despite an agreement on Croatian autonomy negotiated by the Prime Minister, Cvetković, in 1939, emotions against Serbia remained strong. After the German invasion of Yugoslavia in 1941, the Ustase movement was eager to create a Fascist puppet regime as the Independent State of Croatia. Until 1945 its brutal government was responsible for the expulsion or killing of some 600,000 Serbs. In retaliation, once Tito's partisan rebels had established their dominance over the Chetniks, they vented their wrath on the Croatians, slaughtering many Ustase Fascists, as well as innocent Croatians, in return.

The Tito era (1945–80)

With bitterness and hatred between the country's fifteen nationalities at an all‐time high, another attempt at unification could only be made by Tito's iron will. He created the Federal People's Republic of Yugoslavia on 31 January 1946, comprising six republics, the autonomous province of Vojvodina, and the autonomous area of Kosovo. Unfortunately, the differences between the various ethnicities which had intensified so much during the war were never properly addressed or publicly discussed, and were largely suppressed. As the only Eastern European country (apart from Albania) which had become Communist without Moscow's direct help, Tito enjoyed much freedom of manoeuvre owing to the absence of Soviet troops, and he used this to the full.

To Stalin's impotent anger, Tito accepted US aid in 1948, from which time Yugoslavia pursued an independent policy as a leading member of the non‐aligned movement. This enabled Tito to play off US against Soviet support, a game at which he excelled. A new constitution for the Federal Socialist Republic of Yugoslavia was introduced in 1963. Growing nationalist aspirations, most notably the Croatian Spring (1967–72), which produced a Croatian cultural and linguistic revival and was ultimately suppressed by Tito, led to the promulgation of the 1974 constitution, which gave the constituent republics and autonomous provinces more powers. After Tito's death, the presidency was shared between the states in rotation.

Dissolution (1980s–2003)

While it would be wrong to assume that Yugoslavia was already doomed, there were signs that all was not well in 1981, when street riots in Kosovo were brutally suppressed. Thereafter, its autonomy was severely curtailed and was completely abolished in 1989, following renewed violence. This was accompanied by widespread, increasingly open debate about the nature of the Yugoslav state and the viability of Communist single‐party rule. In 1989 the Serbian Communist Party responded to this by ensuring Communist survival through the election of the nationalist Milošević as leader. Together with the Serbian incorporation of Kosovo, this threatened the other republics, where nationalist movements opposed to the Communists emerged. In some ways it was a repeat of the interwar problem, as the attempt by Serb nationalists to gain control of the Yugoslav state apparatus was met with increasing rejection of the Yugoslav state by its other constituent republics.

The formal breakup of Yugoslavia began with the secession of Slovenia in 1991. By 1992, all that remained within Yugoslavia was Serbia and Montenegro, which on 29 April 1992 formed the Federal Republic of Yugoslavia. In 2003, this was transformed into the Union of Serbia and Montenegro, and at this point Yugoslavia formally ceased to exist.