In May 1911, ten men in Serbia formed the Black Hand Secret Society. Early members included Colonel Dragutin Dimitrijevic, the chief of the Intelligence Department of the Serbian General Staff, Major Voja Tankosic and Milan Ciganovic.
The main objective of the Black Hand was the creation, by means of violence, of a Greater Serbia. Its stated aim was: "To realize the national ideal, the unification of all Serbs. This organisation prefers terrorist action to cultural activities; it will therefore remain secret."
Dragutin Dimitrijevic, who used the codename, Apis, established himself as the leader of the Black Hand. In 1911 he sent a member to assassinate Emperor Franz Josef. When this failed, Dimitrijevic turned his attention to General Oskar Potiorek, Governor of the Austrian provinces of Bosnia-Herzegovina. Dimitrijevic recruited Muhamed Mehmedbasic to kill Potiorek with a poisoned dagger. However, Mehmedbasic returned to Belgrade after failing to carry out the task.
By 1914 there were around 2,500 members of the Black Hand. The group was mainly made up of junior army officers but also included lawyers, journalists and university professors. About 30 of these lived and worked in Bosnia-Herzegovina.
Three senior members of the Black Hand group, Dragutin Dimitrijevic, Milan Ciganovic, and Major Voja Tankosic, decided that Archduke Franz Ferdinand should be assassinated. Dimitrijevic was concerned about the heir to the Austro-Hungarian throne, Ferdinand's plans to grant concessions to the South Slavs. Dimitrijevic feared that if this happened, an independent Serbian state would be more difficult to achieve.
When Dragutin Dimitrijevic heard that Archduke Franz Ferdinand was planning to visit Sarajevo in June 1914, he sent three members of the Black Hand group, Gavrilo Princip, Nedjelko Cabrinovic and Trifko Grabez from Serbia to assassinate him. Nikola Pasic, the prime minister of Serbia, Pasic heard about the plot and gave instructions for the three men to be arrested. However, his orders were not implemented and Archduke Franz Ferdinand was assassinated.
Several members of the Black Hand group interrogated by the Austrian authorities claimed that three men from Serbia, Dragutin Dimitrijevic, Milan Ciganovic, and Major Voja Tankosic, had organised the plot. On 25th July, 1914, the Austro-Hungarian government demanded that the Serbian government arrest the men and send them to face trial in Vienna.
On 25th July, 1914, Nikola Pasic, the prime minister of Serbia, told the Austro-Hungarian government that he was unable to hand over these three men as it "would be a violation of Serbia's Constitution and criminal in law". Three days later Austro-Hungarian declared war on Serbia.
During the first two years of the First World War the Serbian Army suffered a series of military defeats. Nikola Pasic, who blamed the Black Hand for the war, and in December 1916 decided to disband the organisation. Dragutin Dimitrijevic and several of the Black Hand leaders were arrested and executed the following year.