Tension existed in Europe especially in the troubled Balkan regions in the southeast of Europe. A number of alliances involved European powers, Ottoman Empire, Russia and other parties had existed for years, but political instability in the Balkans threatened to destroy these agreements, till the spark of the World War I was ignited in Sarajevo, Bosnia, where Archduke Franz Ferdinand and his wife Sophie was shot by Serbian nationalist Gaverilo Princip.
The Austro-Hungarian authorities encouraged the subsequent anti-Serb riots in Sarajevo, in which Bosnian Croats killed 2 Bosnian Serbs and damaged numerous Bosnian Serb assets. violent actions against Serbs were also organized outside Sarajevo, in other Austro-Hungarian controlled in Bosnia and Herzegovina.
In 1914, a political assassination in Sarajevo set off a chain of events that led to the outbreak of World War I. As more and more young men were sent down into the trenches, influential voices in the United States and Britain began calling for the establishment of a permanent international body to maintain peace in the postwar world.
In liberated territories, the Partisans organised People's Committees to act as civilian government. The Anti-Fascist Council of National Liberation of Yugoslavia (AVNOJ) convened in Bihać on 26–27 November 1942.
In the final days of World War II in Yugoslavia, units of the Partisans were responsible for atrocities after the repatriations of Bleiburg, and accusations of culpability were later raised at the Yugoslav leadership under Tito.
On 14 May, he dispatched a telegram to the supreme headquarters Slovene Partisan Army prohibiting the execution of prisoners of war and commanding the transfer of the possible suspects to a military court.
In November 1945, Tito's pro-republican People's Front, led by the Communist Party of Yugoslavia, won the elections with an overwhelming majority, the vote having been boycotted by monarchists.
On 28 June, the other member countries of the Cominform expelled Yugoslavia, citing "nationalist elements" that had "managed in the course of the past five or six months to reach a dominant position in the leadership" of the CPY.
On 26 June 1950, the National Assembly supported a crucial bill written by Milovan Đilas and Tito regarding "self-management", a type of cooperative independent socialist experiment that introduced profit sharing and workplace democracy in previously state-run enterprises, which then became the direct social ownership of the employees.
In September 1976, Carlos was arrested, detained in Yugoslavia, and flown to Baghdad. He chose to settle in Aden, where he tried to found his own Organization of Armed Struggle, composed of Syrian, Lebanese and German rebels. He also connected with the Stasi, East Germany's secret police. They provided him with an office and safe houses in East Berlin, a support staff of 75, and a service car, and allowed him to carry a pistol while in public.
In the First multi-party election in Bosnia and Herzegovina, in November 1990, votes were cast largely according to ethnicity, leading to the success of the Bosniak Party of Democratic Action, the Serbian Democratic Party and the Croatian Democratic Union.
On 15 May, Stjepan Mesić, a Croat, was scheduled to be the chairman of the rotating presidency of Yugoslavia. Serbia, aided by Kosovo, Montenegro, and Vojvodina, whose presidency votes were at that time under Serbian control, blocked the appointment, which was otherwise seen as largely ceremonial.
On 18 November 1991, the Croatian Community of Herzeg-Bosnia was established in Mostar. Mate Boban was chosen as its president. Its founding document said: "The Community will respect the democratically elected government of the Republic of Bosnia and Herzegovina for as long as exists the state independence of Bosnia and Herzegovina in relation to the former, or any other, Yugoslavia".
After the fall of the Berlin Wall in Germany in 1989, the organization conducted its first military interventions in Bosnia from 1992 to 1995 and later Yugoslavia in 1999 during the breakup of Yugoslavia.
Milošević denounced the declaration of independence of Bosnia and Herzegovina from Yugoslavia in 1992, and said that "Bosnia and Herzegovina was illegally proclaimed as an independent state and recognized.
The Bosnian Serb assembly members advised Serbs to boycott the referendums held on 29 February and 1 March 1992. The turnout to the referendums was reported as 63.7%, with 92.7% of voters voting in favour of independence (implying that Bosnian Serbs, which made up approximately 34% of the population, largely boycotted the referendum).
on 28 March 1992, Izetbegović, after meeting with the then-US ambassador to Yugoslavia Warren Zimmermann in Sarajevo, withdrew his signature and declared his opposition to any type of ethnic division of Bosnia.
From May to December 1992, the Bosnian Ministry of the Interior (BiH MUP), Croatian Defence Council (HVO) and later the Bosnian Territorial Defence Forces (TO RBiH) operated the Čelebići prison camp. It was used to detain 700 Bosnian Serb prisoners of war arrested during military operations that were intended to de-block routes to Sarajevo and Mostar in May 1992 which had earlier been blocked by Serb forces. Of these 700 prisoners, 13 died while in captivity.
On 15 May 1992, a JNA column was ambushed in Tuzla. 92nd Motorised JNA Brigade (stationed in "Husinska buna" barracks in Tuzla) received orders to leave the city of Tuzla and Bosnia-Herzegovina, and to enter Serbia.
The Army of Republika Srpska was newly established and put under the command of General Ratko Mladić, in a new phase of the war. Shelling on Sarajevo on 24, 26, 28 and 29 May were attributed to Mladić by UN Secretary-General Boutros Boutros-Ghali.
In 1992, the Croat-Bosniak conflict erupted in Bosnia and Herzegovina, just as each was fighting with the Bosnian Serbs. The war was originally fought between the Croatian Defense Council and Croatian volunteer troops on one side and the Army of the Republic of Bosnia and Herzegovina (ARBiH) on the other, but by 1994, the Croatian Army had an estimated 3,000 to 5,000 troops involved in the fighting.
On 7 January 1993, Orthodox Christmas Day, 8th Operational Unit Srebrenica, a unit of the ARBiH under the command of Bratunac Killings, attacked the village of Kravica near Bratunac. 46 Serbs died in the attack: 35 soldiers and 11 civilians.
By 26 January, the ARBiH seized control of several villages in the area, including Kaćuni and Bilalovac on the Busovača–Kiseljak road, thus isolating Kiseljak from Busovača. In the Kiseljak area, the ARBiH secured the villages northeast of the town of Kiseljak, but most of the municipality and the town itself remained in HVO control.
On 30 January, ARBiH and HVO leaders met in Vitez, together with representatives from UNPROFOR and other foreign observers, and signed a ceasefire in the area of central Bosnia, which came into effect on the following day.
On 22 February 1993, the United Nations Security Council passed Resolution 808 that decided "that an international tribunal shall be established for the prosecution of persons responsible for serious violations of international humanitarian law".
The April incidents escalated into an armed conflict on 15 April in the area of Vitez, Busovača, Kiseljak and Zenica. The outnumbered HVO in the Zenica municipality was quickly defeated, followed by a large exodus of Croat civilians.
On 16 April, the HVO (The Croatian Defence Council) launched a spoiling attack on the village of Ahmići, east of Vitez. After the attacking units breached the ARBiH lines and entered the village, groups of irregular HVO units went from house to house, burning them and killing civilians.
On 24 April, mujahideen forces attacked the village of Miletići northeast of Travnik and killed four Croat civilians. The rest of the captured civilians were taken to the Poljanice camp.
A similar development took place in Novi Travnik. On 9 June, the ARBiH (Army of the Republic of Bosnia and Herzegovina) attacked HVO units positioned east of the town, facing the VRS in Donji Vakuf, and the next day heavy fighting followed in Novi Travnik.
By 15 June, the ARBiH secured the area northwest of the town, while the HVO kept the northeastern part of the municipality and the town of Novi Travnik. The battle continued into July with only minor changes on the front lines.
On 5 February 1994, Sarajevo suffered its deadliest single attack of the entire siege with the first Markale massacre, when a 120 millimeter mortar shell landed in the centre of the crowded marketplace, killing 68 people and wounding another 144.
On 9 February 1994, NATO authorized the Commander of Allied Forces Southern Europe (CINCSOUTH), US Admiral Jeremy Boorda, to launch air strikes—at the request of the UN—against artillery and mortar positions in or around Sarajevo determined by UNPROFOR to be responsible for attacks against civilian targets.
On 12 March 1994, the United Nations Protection Force (UNPROFOR) made its first request for NATO air support, but close air support was not deployed, owing to a number of delays associated with the approval process.
On 20 March an aid convoy with medical supplies and doctors reached Maglaj, a city of 100,000 people, which had been under siege since May 1993 and had been surviving off food supplies dropped by US aircraft. A second convoy on 23 March was hijacked and looted.
On 10–11 April 1994, UNPROFOR called in air strikes to protect the Goražde safe area, resulting in the bombing of a Serbian military command outpost near Goražde by two US F-16 jets.
Around 29 April 1994, a Danish contingent (Nordbat 2) on peacekeeping duty in Bosnia, as part of UNPROFOR's Nordic battalion located in Tuzla, was ambushed when trying to relieve a Swedish observation post (Tango 2) that was under heavy artillery fire by the Bosnian Serb Šekovići brigade at the village of Kalesija.
On 5 August, at the request of UNPROFOR, NATO aircraft attacked a target within the Sarajevo Exclusion Zone after weapons were seized by Bosnian Serbs from a weapons collection site near Sarajevo.