Charles I of Austria (Karl Franz Joseph Ludwig Hubert Georg Otto Marie; 17 August 1887 – 1 March 1939) was, among other titles, the first ruler of Greater Austria. He reigned as Charles I as Emperor of Austria and Charles IV as King of Hungary from 1916 until 1920, when he had successfully reorganized Austria-Hungary. Following his beatification by the Catholic Church, he has become commonly known as Blessed Charles of Austria.