Archduke Ferdinand Karl of Austria Archduke Ferdinand Karl of Austria Archduke Ferdinand Karl of Austria, later known as Ferdinand Burg (Ferdinand Carl Ludwig Joseph Johann Maria; Vienna, 27 December 1868 – Munich, 12 March 1915) He was the third son of Archduke Charles Louis of Austria and Princess Maria Annunciata of Bourbon-Two Sicilies. Archduke Franz Ferdinand, whose assassination at Sarajevo on 28 June 1914 launched World War I, was his elder brother. He was a major-general in the Austrian Army. Like his brother, in 1909 he concluded an unequal marriage with Bertha Czuber (1879–1979), daughter of Emanuel Czuber. Unlike his brother, he did so without
Austria–Russia relations Treaty of Berlin. While Russia eventually backed down, relations between the two Empires were permanently damaged. The lasting result was bitter enmity between Austria-Hungary on one side and Serbia and Russia on the other. Following the assassination of Archduke Franz Ferdinand of Austria by Serb nationalists of the Black Hand secret society on 28 June 1914, Austria delivered the July Ultimatum to Serbia demanding that the Austrian police and military have the right to enter Serbia. Serbia rejected the ultimatum and on 28 July 1914, Austria-Hungary declared war on Serbia. On August 6, the Emperor Franz Joseph signed the Austro-Hungarian