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
Franz Joseph I of Austria the Empire on 6 October 1908. However a diplomatic crisis erupted, as both the Serbs and the Italians demanded compensation for the annexation, which the Austro-Hungarian government refused to entertain. The incident was not resolved until the revision of the Treaty of Berlin in April 1909, exacerbating tensions between Austria-Hungary and the Serbs. On 28 June 1914 Franz Joseph's nephew and heir Archduke Franz Ferdinand, and his morganatic wife Sophie, Duchess of Hohenberg, were assassinated by Gavrilo Princip, a Yugoslav nationalist of Serbian ethnicity, during a visit to Sarajevo. When he heard the news of the assassination, Franz Joseph said