Archduke Franz Ferdinand of Austria, heir presumptive to the Austro-Hungarian throne, and his wife, Sophie, Duchess of Hohenberg, were assassinated on 28 June 1914 by Bosnian Serb student Gavrilo Princip, shot at close range while being driven through Sarajevo, the provincial capital of Bosnia-Herzegovina, formally annexed by Austria-Hungary in 1908.

Princip was part of a group of six Bosnian assassins together with Muhamed Mehmedbai, Vaso ubrilovi, Nedeljko abrinovi, Cvjetko Popovi and Trifko Grabe coordinated by Danilo Ili; all but one were Bosnian Serbs and members of a student revolutionary group that later became known as Young Bosnia. The political objective of the assassination was to free Bosnia and Herzegovina of Austria-Hungarian rule and establish a common South Slav ("Yugoslav") state. The assassination precipitated the July Crisis which led to Austria-Hungary declaring war on Serbia and the start of World War I.

The assassination team was helped by the Black Hand, a Serbian secret nationalist group; support came from Dragutin Dimitrijevi, at the time chief of the military intelligence section of the Serbian general staff, as well as from Major Vojislav Tankosi and Rade Malobabi, a Serbian intelligence agent. Tankosi provided bombs and pistols to the assassins and trained them in their use. The assassins were given access to the same clandestine network of safe-houses and agents that Malobabi used for the infiltration of weapons and operatives into Austria-Hungary.

The assassins and key members of the clandestine network were tried in Sarajevo in October 1914. In total twenty-five people were indicted. All six assassins, except Mehmedbai, were under twenty at the time of the assassination; while the group was dominated by Bosnian Serbs, four of the indictees were Bosnian Croats, and all of them were Austro-Hungarian citizens, none from Serbia. Princip was found guilty of murder and high treason; too young to be executed, he was sentenced to twenty years in jail, while the four other attackers also received jail terms. Five of the older prisoners were sentenced to be hanged.

Black Hand members were arrested and tried before a Serbian court in Salonika in 1917 on fabricated charges of high treason; the Black Hand was disbanded and three of its leaders were executed. Much of what is known about the assassinations comes from these two trials and related records. Princip's legacy was re-evaluated following the breakup of Yugoslavia, and public opinion of him in the successor states is largely divided along ethnic lines.

Austria-Hungary, often referred to as the Austro-Hungarian Empire or the Dual Monarchy, was a constitutional monarchy and great power in Central Europe between 1867 and 1918. It was formed with the Austro-Hungarian Compromise of 1867 and was dissolved shortly after its defeat in the First World War.

At its core was the dual monarchy which was a real union between Cisleithania, the northern and western parts of the former Austrian Empire, and the Kingdom of Hungary. A third component of the union was the Kingdom of Croatia-Slavonia, an autonomous region under the Hungarian crown, which negotiated the Croatian–Hungarian Settlement in 1868. From 1878, Austria-Hungary jointly governed Bosnia-Herzegovina, which it annexed in 1908. Austria-Hungary was ruled by the House of Habsburg and constituted the last phase in the constitutional evolution of the Habsburg Monarchy. The union was established by the Austro-Hungarian Compromise on 30 March 1867 in the aftermath of the Austro-Prussian War. Following the 1867 reforms, the Austrian and Hungarian states were co-equal in power. The two states conducted common foreign, defense, and financial policies, but all other governmental faculties were divided among respective states.

Austria-Hungary was a multinational state and one of Europe's major powers at the time. Austria-Hungary was geographically the second-largest country in Europe after the Russian Empire, at 621,538 km2 (239,977 sq mi) and the third-most populous (after Russia and the German Empire). The Empire built up the fourth-largest machine building industry in the world, after the United States, Germany, and the United Kingdom. Austria-Hungary also became the world's third-largest manufacturer and exporter of electric home appliances, electric industrial appliances, and power generation apparatus for power plants, after the United States and the German Empire.After 1878, Bosnia and Herzegovina came under Austro-Hungarian military and civilian rule until it was fully annexed in 1908, provoking the Bosnian crisis among the other powers. The northern part of the Ottoman Sanjak of Novi Pazar was also under de facto joint occupation during that period, but the Austro-Hungarian army withdrew as part of their annexation of Bosnia. The annexation of Bosnia also led to Islam being recognized as an official state religion due to Bosnia's Muslim population .Austria-Hungary was one of the Central Powers in World War I, which began with an Austro-Hungarian war declaration on the Kingdom of Serbia on 28 July 1914. It was already effectively dissolved by the time the military authorities signed the armistice of Villa Giusti on 3 November 1918. The Kingdom of Hungary and the First Austrian Republic were treated as its successors de jure, whereas the independence of the West Slavs and South Slavs of the Empire as the First Czechoslovak Republic, the Second Polish Republic, and the Kingdom of Yugoslavia, respectively, and most of the territorial demands of the Kingdom of Romania were also recognized by the victorious powers in 1920.