in July 1908. Black Hand Following the Austro-Hungarian annexation of Bosnia and Herzegovina (October 6, 1908), Tankosić established a Chetnik school in Prokuplje, in which volunteers were trained to execute special operations in Bosnia and Herzegovina. He spread the network throughout Bosnia and Herzegovina, and recruited volunteers for a conflict he believed was inevitable. This was contrary to the policy of the Serbian government, which feared Austro-Hungary. Some 5,000 volunteers were organized in Serbia. Austrian and Hungarian newspapers reported that there were 1,000 bands in Serbia, with 20 well-armed fighters in each, and that each fighter would give one of his two guns to Bosnian rebels. However, when Serbia recognized the annexation in 1909, the training camp in Ćuprija was closed down; the military knowledge that was gained was useful in the coming war. He was a member of the Young Bosnia and one of the founders of Unification or Death (popularly known as the "Black Hand"). Together with Bogdan Radenković and Ljuba Jovanović-Čupa, he wrote the constitution of the organization, whose aim was to fight for the unification of Serbdom. Balkan Wars Before the outbreak of the war in March 1912, Tankosić was transferred to the headquarters of the border troops, tasked with training volunteers who arrived from all Serb-inhabited regions. Tankosić was very strict in his selection, and out of 2,000 candidates, he chose only 245 volunteers. One who was declined was Gavrilo Princip, due to his weak stature. The Serbian government tried to use the Albanians against the Turks, and sent Tankosić to Kosovo where he slipped weapons to Albanian leaders. Together with Isa Boletini, he led local Albanians in June and July 1912 in their conflict with Turks around Mitrovica. In the First Balkan War Tankosić commanded the Laplje Chetnik detachment. The detachment began operations in the Turkish background two days before the outbreak of the war, at the border post (karaula) at Merdare, where the Chetniks and Albanians skirmished into the first battle of the war. It seems that they began fighting on their own initiative, without the approval of superiors. There is a possibility that the Black Hand feared agreement between Turkey and the Balkan allies, which would hold back the liberation of Serb-inhabited territories. The Chetniks fought for three days by themselves, until the regular Serbian Army joined in. The Serbian Army brought victory, and Tankosić's Chetniks were the first to enter Pristina. Tankosić's Chetniks thus opened the door for the Serbian Army to liberate Kosovo, and Tankosić was awarded the Order of the Star of Karađorđe with Swords and promoted to major. 1913 and Archduke assassination plot Together with the other members of the Black Hand, Tankosić pressured the Serbian government of Nikola Pašić before the Treaty of Bucharest (1913). The government tried to retire Tankosić and Apis; however, the King disagreed. A conflict between the military and civilian authorities simmered during 1913 and escalated during 1914, with open threats made to certain ministers. It is claimed that he participated in the training of the assassins of Archduke Franz Ferdinand, arranged to smuggle them across the Drina, and had his agent Ciganovic provide them with weapons. After the 1914 assassination, the Austro-Hungarian government gave an ultimatum to the Serbian government, whom they held responsible for the assassination; Tankosić was thus imprisoned in the headquarters of the Danube Division I. He was forgiven when Austria attacked Serbia. World War I After the outbreak of World War I, Tankosić became the commander of the Volunteer Squad in Belgrade, and then the Rudnik Volunteer Squad. By the time of the Battle of Drina (1914), he