Complex sentence: Archduke Franz Ferdinand and his wife Duchess Sophie through Sarajevo were blown up by an assassin's bomb on June 28,1914, Austria-Hungary issued a number of ultimata against Serbia, which was supported by Russia.
Split into simpler sentences: Archduke Franz Ferdinand and his wife Duchess Sophie through Sarajevo were blown up by an assassin's bomb on June 28,1914. After the assassination, Austria-Hungary issued a number of ultimata against Serbia, which was supported by Russia.