THIS DAY IN RMR HISTORY: July 24, 1914, the Serbian regent, Alexander sent a telegram to Russian Tsar Nicholas II in the middle of the so-called July Crisis of 1914. One day earlier the Austro-Hungarian government had given Serbia a harsh ultimatum in response to the assassination of Austrian Archduke Franz Ferdinand on June 28th. This ultimatum gave Serbia 48 hours to respond and was made public at the same time the Regent’s telegram was sent to the Tsar.
In his telegram Alexander appealed to the Tsar for assistance in dealing with Austria-Hungary’s increasingly menacing stance against Serbia. Although Russia proved willing to help Serbia it was to no avail. Austria-Hungary declared war against Serbia on 28 July 1914, sparking off the onset of the First World War.
Source: http://www.firstworldwar.com/source/serbianappealforhelp.htm