Archduke Franz Ferdinand of Austria and his wife Sophie are assassinated in Sarajevo; this is the casus belli of World War I.
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.
Archduke Franz Ferdinand Carl Ludwig Joseph Maria of Austria (18 December 1863 – 28 June 1914) was the heir presumptive to the throne of Austria-Hungary. His assassination in Sarajevo is considered the most immediate cause of World War I.
Franz Ferdinand was the eldest son of Archduke Karl Ludwig of Austria, the younger brother of Emperor Franz Joseph I of Austria. Following the death of Crown Prince Rudolf in 1889 and the death of Karl Ludwig in 1896, Franz Ferdinand became the heir presumptive to the Austro-Hungarian throne. His courtship of Sophie Chotek, a lady-in-waiting, caused conflict within the imperial household, and their morganatic marriage in 1900 was only allowed after he renounced his descendants' rights to the throne. Franz Ferdinand held significant influence over the military, and in 1913 he was appointed inspector general of the Austro-Hungarian armed forces.
On 28 June 1914, Franz Ferdinand and his wife were assassinated in Sarajevo by the 19-year-old Gavrilo Princip, a member of Young Bosnia. Franz Ferdinand's assassination led to the July Crisis and precipitated Austria-Hungary's declaration of war against Serbia, which in turn triggered a series of events that eventually led to Austria-Hungary's allies and Serbia's allies declaring war on each other, starting World War I.