Original: From this matrimony he had two sons: Duke Anton Aleksandrovich (around 1891, - Rostov on Don, 1950) Duke Bagrat Aleksandrovich (1892, - Kafan, 1981) During the revolution in Petrograd in the year 1917, duke Aleksandr and his wife duchess Sofia were killed by the Bolsheviks.
Simplified: During the revolution in Petrograd in 1917, Duke Aleksandr and his wife were killed by the Bolsheviks.