Complex sentence: He died in year 1977 at Bombay, without an issue, when the Rana Sahib Natwarsinhji Bhavsinhji, the Maharaja of Porbandar, was still alive, who died in year 1979.
Split into simpler sentences: He died in year 1977 at Bombay, without an issue. When he died, the Rana Sahib Natwarsinhji Bhavsinhji, the Maharaja of Porbandar, was still alive, who died two years later in year 1979.