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
SMS Viribus Unitis above the casemates. Three more 7 cm K10 guns were mounted on the upper turrets for anti-aircraft duties. Four submerged torpedo tubes were fitted, one each in the bow, stern and on each broadside; twelve torpedoes were carried. Archduke Franz Ferdinand of Austria travelled aboard "Viribus Unitis" in late June 1914 en route to Bosnia to observe military manoeuvres. On 25 June, he boarded the ship in Trieste Harbour and travelled to the mouth of the Neretva River, where he transferred to another vessel. On 30 June, two days after Ferdinand and his wife were killed by Gavrilo Princip in