Karl became the heir to the throne after the death of his uncle Franz Ferdinand in 1914, and emperor following the death of Franz Joseph I in the middle of the First World War. In 1918 he was forced to renounce participation in the affairs of state of Austria and Hungary, but refused to abdicate. Karl emigrated with his family to Switzerland. In 1921 he made two vain attempts to restore the monarchy in Hungary. He was then interned by the Allies on Madeira, where he died only a few months later.