Franz Joseph I of Austria the Empire on 6 October 1908. However a diplomatic crisis erupted, as both the Serbs and the Italians demanded compensation for the annexation, which the Austro-Hungarian government refused to entertain. The incident was not resolved until the revision of the Treaty of Berlin in April 1909, exacerbating tensions between Austria-Hungary and the Serbs. On 28 June 1914 Franz Joseph's nephew and heir Archduke Franz Ferdinand, and his morganatic wife Sophie, Duchess of Hohenberg, were assassinated by Gavrilo Princip, a Yugoslav nationalist of Serbian ethnicity, during a visit to Sarajevo. When he heard the news of the assassination, Franz Joseph said
Emperor of Austria in 1875. As Ferdinand I had no sons, his brother Francis Charles would have become emperor, but was persuaded by his wife to pass over the right of succession to their son, Francis Joseph. He accepted the duty of the Emperor of Austria without having been Crown Prince or "Thronfolger" before. Francis Joseph's only son Rudolf committed suicide in 1889, Francis Joseph's brother Karl Ludwig died in 1896. Karl Ludwig's son Franz Ferdinand became heir presumptive to the throne. He was assassinated in Sarajevo, Bosnia in 1914; due to his morganatic marriage, his son had no rights to the throne.