SMS Kaiser Karl VI and Argentina. On 25 May, she represented Austria-Hungary at the centennial of Argentina's May Revolution, which won the country's independence from Spain. On 28 June 1914, Archduke Franz Ferdinand, the heir to the Austro-Hungarian throne, was assassinated in Sarajevo; the assassination sparked the July Crisis and ultimately the First World War, which broke out a month later on 28 July. The German battlecruiser , which had been assigned to the Mediterranean Division, sought the protection of the Austro-Hungarian fleet, and so Admiral Anton Haus sent the fleet, including "Kaiser Karl VI", south on 7 August to assist his German ally.
History of Russia (1892–1917) was Serbia's territorial rival in the region, and Germany remained the Ottoman Empire's protector. Russia tied itself more closely to Serbia than it had previously. The complex system of alliances and Great Power support was extremely unstable; among the Balkan parties harboring resentments over past defeats, the Serbs maintained particular animosity toward the Austro-Hungarian annexation of Bosnia and Herzegovina. In June 1914, a Serbian terrorist assassinated Archduke Franz Ferdinand, heir to the throne of Austria–Hungary, which then held the Serbian government responsible. Austria–Hungary delivered an ultimatum to Serbia. Serbia submitted to the first 2 of 3 cases of the ultimatum;