Austria didn't have a President in 1914. It was part of the Austro-Hungarian Empire, which was ruled by an Emperor. In 1914, the Emperor was Franz Josef; he died two years later and was succeeded by his great nephew Karl I.
The assassination of Archduke Franz Ferdinand of Austria, by Gavrilo Princip on June 28, 1914. On July 23, 1914, Austria set an ultimatum for Serbia to leave Austria. This ultimatum would expire on July 28, 1914. When the Serbs would still not leave, Austria declared war on Serbia.