Archduke Franz Ferdinand Carl Ludwig Joseph Maria of Austria (18 December 1863 – 28 June 1914) was the heir presumptive to the throne of Austria-Hungary. His assassination in Sarajevo is considered the most immediate cause of World War I.
It denotes a rank within the former Holy Roman Empire (962–1806), which was below that of Emperor and King, roughly equal to Grand Duke, but above that of a Prince and Duke. The territory ruled by an Archduke or Archduchess was called an Archduchy. All remaining Archduchies ceased to exist in 1918.