Greater Serbia the Kingdom of Serbia retreated from Durrës in April 1913 under pressure of the naval fleet of Great Powers, but it remained in other parts of Albania for the next two months. The secret military society called Unity or Death, popularly known as the Black Hand, headed by Serbian colonel Dragutin Dimitrijević Apis, which took an active and militant stance on the issue of a Greater Serbian state. This organization is believed to have been responsible for numerous atrocities following the Balkan Wars in 1913. In 1914, Young Bosnia member Gavrilo Princip assassinated Archduke Franz Ferdinand in Sarajevo, which set
Serbs of Croatia of the World War I, all organizations that the government considered favored unification of South Slavs or Serbia, which was on the side of the Allied Powers, were banned. Josip Frank's associates took advantage of some provocations and the anger of the people after the assassination of Archduke Franz Ferdinand by Serb Gavrilo Princip and organized anti-Serbian demonstrations. After a stone was thrown on a parade in which the image of Franz Ferdinand was carried true Zagreb, many cafés and gathering places of pro-Yugoslav politicians as well as Serb-owned shops were demolished. Croat-Serb Coalition MP's were also attacked. On the