Probably the first "official" mention of the term Yugoslav (as opposed to simply south Slav) was the forming of the group of advocates of a joint country of South Slavs, by politicians from Croatia and Bosnia and Herzegovina, which were then both in the Austro-Hungarian Monarchy.
On November 22, 1914, Ante Trumbić, Frano Supilo, Ivan Meštrović, Hinko Hinković and Franko Potočnjak from Croatia and Nikola Stojanović and Dušan Vasiljević from Bosnia and Herzegovina first met with Pavle Popović, a representative of Nikola Pašić's Serbian government, on neutral ground in Florence, Italy, in an effort to coordinate their efforts towards building an independent state of western South Slavs. Lujo Vojnović was also present as an observer from the Kingdom of Montenegro.
The new "Yugoslav" cause (from Jugoslav, meaning "Southern Slav") was receiving an increasing amount of support: in the western states, the people were generally tired of Austria-Hungary and a union with the eastern states was probably seen as the best way to come out of the anomie caused by the Great War. Even the large diasporas, known for their nostalgia and patriotism, started supporting the new idea.
The Yugoslav Committee (Jugoslavenski odbor) was officially formed on April 30th, 1915 in London, and the aforementioned politicians were its members. The Committee and the Kingdom of Serbia subsequently signed the Corfu Declaration on July 20, 1917 that declared their desire to form a new joint kingdom.
The goals of the Yugoslav Committee were partly reached by the end of the First World War in 1918, when Austria-Hungary disintegrated, and the South Slavs organized into the State of Slovenes, Croats and Serbs. This short-lived state soon, on December 1, 1918, joined Serbia and Montenegro to form "The Kingdom of Serbs, Croats and Slovenes".
On June 28 1921, — a day of historical importance to Serbs (see Vidovdan) — parliament (Skupština) passed a new constitution despite a boycott from Croatian MPs. The constitution centralized political authority and strengthened the power of the royal government in Belgrade.
In 1928, Puniša Račić, an ethnic Serbian nationalist leader from Montenegro, shot and killed Croatian Peasant Party leader Stjepan Radić in the parliament chambers. King Aleksandar used the shooting as a pretext to strengthen his power and on January 6, 1929 he suspended the constitution, dissolved the Skupština and proclaimed a royal dictatorship. He went on to reorganize the regional divisions within the country and renamed it the Kingdom of Yugoslavia. All national identities except "Yugoslav" were abolished.
Yugoslavia became a highly militarized state, which spawned several insurgent nationalist groups opposed to the royal dictatorship. The king was highly unpopular, particularly among non-Serbs, and while on a visit to Marseille, France in 1934, he was assassinated by Macedonian nationalists.
In the beginning of World War II, Yugoslavia was pressured by Germany and Italy to join the Axis powers. Italy was mired in an inconclusive war with Greece, and before Germany committed its forces to the Greek campaign, it wanted to secure Yugoslavia's support.
Royal Regent Paul submitted to the fascist pressure and signed the Tripartite Treaty in Vienna on March 25, 1941, hoping to still keep Yugoslavia out of the war. But this was at the expense of popular support for Paul's regency. Senior military officers were also opposed to the treaty and launched a coup d'état when the king returned on March 27. Army General Dusan Simovic seized power, arrested the Vienna delegation, exiled Paul, and instated the 17-year old crown prince Peter as the new king. Apparently this defiance infuriated Hitler, so the Axis decided to attack both Yugoslavia and Greece on April 6. (As a result, Hitler had to delay the launch of Operation Barbarossa by four weeks, which proved to be a costly decision.)
At 05:15 on April 6 1941, German, Italian, Hungarian, and Bulgarian forces attacked Yugoslavia. The Luftwaffe bombed Belgrade and other major Yugoslav cities. On April 17, representatives of Yugoslavia's various regions signed an armistice with Germany at Belgrade, ending eleven days of resistance against the invading German Wehrmacht. More than three hundred thousand Yugoslav officers and soldiers were taken prisoner. The Axis powers occupied Yugoslavia and split it up. The Independent State of Croatia was established as a Nazi puppet-state, ruled by the far-right militia Ustaše. German troops occupied part of Serbia and Slovenia, while other parts of the country went back to Albania, Bulgaria, Hungary and Italy.
Yugoslavs opposing the Nazis joined the Yugoslav National Liberation Army, led by Josip Broz Tito, a Croatian member of the Communist Party of Yugoslavia. The NLA staged a wide-spread guerrilla campaign, and the Germans answered by punishing the civil population. This led to great losses for Yugoslavia, approximately one million people (the demographic loss was 1,700,000 people or 10% of the population). In liberated territories, NLA organized people's committees to act as civilian government. On November 25, 1942, the Anti-Fascist Council of National Liberation of Yugoslavia was convened in Bihać. The council reconvened on November 29, 1943 in Jajce and established the basis for post-war organisation of the country, establishing a federation (this date was celebrated as Republic Day after the war).
The NLA was able to expel the Axis from Serbia in 1944 and the rest of Yugoslavia in 1945. The Red Army aided in liberating Belgrade. During the war the communist lead the partisans that were opposing the occupation and were de facto rulers on the liberated territories, but also denied supremacy of the old Kingdom of Yugoslavia government. Westerner attempts to reunite partisans and emigration loyal to the king led to the Tito-Subasic Agreement in June 1944, however Tito was seen as a national hero by the citizens and so he gained the power in post-war independent communist state, starting as a prime minister.
The country distanced itself from the Soviets in 1948 (cf. Cominform and Informbiro) and started to build its own way to socialism under strong political leadership of Josip Broz Tito. The country criticized both Eastern and Western block and together with other countries started the Non-Aligned Movement in 1961, which remained the official policy of the country until it dissolved.
In SFRY, each republic had its own constitution, supreme court, parliament, president and prime minister. At the top of the Yugoslav government was a collective Presidency, the federal Prime Minister, and the federal Parliament. An important role was one of the president of the Communist Party of Yugoslavia for each republic, and the president of presidency of Central Committee of the Communist Party.
Josip Broz Tito was the most powerful person in the country, and after him there were republic premiers and presidents, plus Communist Party presidents. There were also people that were secretaries of sectors invented ad hoc by Tito for people he favored. People whom he did not favor varied greatly. Slobodan Penezić Krčun served under Tito and then after he started to complain about his politics, he was found killed under unknown circumstances. Aleksandar Ranković lost all of his titles and rights after a major disagreement with Tito regarding state politics. Sometimes ministers in government were more important than the premier, such as in the case of Edvard Kardelj or Stane Dolanc.
The suppression of national identities escalated with the so-called Croatian Spring of 1970-71, when students in Zagreb organized demonstrations for greater civil liberties and greater Croatian autonomy. The regime stifled the public protest and incarcerated the leaders, but many key Croatian representatives in the Party silently supported this cause, so a new Constitution was ratified in 1974 that gave more rights to the individual republics. According to this constitution, individual republics had a right for self-determination, up to secession, which made later break-up easier.
After Tito's death in 1980, ethnic tension grew in Yugoslavia. Serbian communist leader Slobodan Milošević, the new strong man of Yugoslavia, tried to play on the revived Serb nationalism, but ended up alienating all the other ethnic groups in the federation.
The Serbian Academy of Sciences and Arts published a memorandum in the 1980s that opposed the policy of the federation and promoted Serbian nationalism. The ethnic Albanian miners in Kosovo organized strikes which turned out to be an ethnic conflict between the Albanian majority and the Serbian minority in the province. Milošević's people organized the abolition of the autonomous provinces of Vojvodina and Kosovo, though peculiarly enough both entities retained a vote in the Yugoslav Presidency Council.
In January 1990, the extraordinary 14th Congress of the League of Communists of Yugoslavia was convened. The delegation of Serbia led by Milošević insisted on the reversal of 1974 Constitution policy that empowered the republics and rather wanted to introduce a policy of "one person, one vote", which would empower the majority population, the Serbs. This caused the Slovenian and Croatian delegations (led by Milan Kučan and Ivica Račan, resp.), which instead favored more economic liberalization (such as perestroika), to leave the Congress in protest, and marked a culmination in the rift of the ruling party.
Following the fall of Communism in Eastern Europe and in Yugoslavia, each of the republics elected a new government democratically, but the unresolved issues remained. In particular, Slovenia and Croatia elected governments oriented towards independence (under Milan Kučan and Franjo Tuđman, respectively), while Serbia and Montenegro elected unionists.
In March 1990, the Yugoslav People's Army (Jugoslavenska Narodna Armija, JNA) met with the Presidency of Yugoslavia (an eight member council composed of representatives from six republics and two autonomous provinces) in an attempt to get them to declare a state of emergency which would allow for the army to take control of the country. The representatives of Serbia, Montenegro, Kosovo and Metohia and Vojvodina voted for the decision, while Croatia (Stipe Mesić), Slovenia (Janez Drnovšek), Macedonia (Vasil Tupurkovski) and Bosnia (Bogić Bogićević) voted against. The tie somewhat delayed escalation of conflicts, but not for long.
Following the first multi-party election results, republics of Slovenia and Croatia proposed to transform Yugoslavia into loose confederation of six republics in Autumn 1990, however Milosevic rejected all such proposals with an argument that all Serbs should live in the same country. Slovenia and Croatia declared independence from Yugoslavia in 1991; Macedonia followed in 1992 together with Bosnia-Herzegovina, albeit only two out of three constitutive peoples, Bosniaks and Croats.
Secession of the new-formed states marked the beginning of the bloody and gruesome Yugoslav wars. It started with a short war in Slovenia and continued with a war in Croatia in 1991 and in Bosnia in 1992. As a result of the conflict, the United Nations Security Council unanimously adopted UN Security Council Resolution 721 on November 27, 1991, which paved the way to the establishment of peacekeeping operations in Yugoslavia.
The Socialist Federal Republic of Yugoslavia officially ceased to exist on April 28, 1992, when the Federal Republic of Yugoslavia (FRY) was formed. Other dates that are frequently considered as the end of SFRY are June 25, 1991, when Slovenia declared independence, October 9, 1991, when the moratorium on Slovenian and Croatian secession, agreed on July 9 at Brioni (see detailed entry at Brioni Agreement) by representatives of all republics, was ended and January 15, 1992, when Slovenia and Croatia were internationally recognized.
After some years of peace, in 1998, UCK started terrorist actions in the southern Serbian province. In 1999 NATO bombed Serbia and Montenegro for more than two months (see Kosovo War). Since June 1999, the province has been governed by peace-keeping forces from NATO and Russia, although all parties continue to recognise it as a part of Serbia.
Milošević's rejection of claims of a first-round opposition victory in new elections for the Federal presidency in September 2000 led to mass demonstrations in Belgrade on October 5 and the collapse of the regime's authority. The opposition's candidate, reformed nationalist Vojislav Koštunica took office as Yugoslav president on October 6.
On April 1, 2001, Milošević was arrested on charges of abuse of power and corruption. On June 28 he was extradited to the United Nations International Criminal Tribunal for the Former Yugoslavia. His trial on charges of genocide in Bosnia and war crimes in Croatia and Kosovo and Metohia began at The Hague on February 12, 2002. On April 11, the Yugoslav parliament passed a law allowing extradition of all persons charged with war crimes by the International Criminal Tribunal.
In March 2002, the Governments of Serbia and Montenegro agreed to reform FRY in favour of a new, much weaker form of cooperation called Serbia and Montenegro. By order of Yugoslav Federal Parliament on February 4, 2003, Yugoslavia ceased to exist.