Battle of Kolubara their respective commands, and the 5th and 6th armies were merged into a single 5th Army of 95,000 men. On 28 June 1914, Bosnian Serb student Gavrilo Princip assassinated Archduke Franz Ferdinand of Austria in Sarajevo. The assassination precipitated the July Crisis, which led Austria-Hungary to issue an ultimatum to Serbia on 23 July on suspicion that the assassination had been planned in Belgrade. The Austro-Hungarian government made the ultimatum intentionally unacceptable to Serbia, and it was indeed rejected. The Austro-Hungarians declared war on Serbia on 28 July and that same day the Serbs destroyed all bridges on the Sava
Archduke Franz Ferdinand of Austria in 1896. Henceforth, Franz Ferdinand was groomed to succeed to the throne. Despite this burden, he did manage to find time for travel and personal pursuits, such as his circumnavigation of the world between 1892 and 1893. After visiting India he spent time hunting kangaroos and emus in Australia in 1893, then travelled on to Nouméa, New Hebrides, Solomon Islands, New Guinea, Sarawak, Hong Kong and Japan. After sailing across the Pacific on the RMS "Empress of China" from Yokohama to Vancouver he crossed the United States and returned to Europe. The Archduke and his wife visited England in the