Complex sentence: The Bolsheviks had attacked his patriarchal vision of Georgian culture and, it was widely believed, had decided to kill him; there is some evidence that Stalin's friend Sergo Ordzhonikidze organized or took part in the assassination.
Split into simpler sentences: The Bolsheviks had attacked his patriarchal vision of Georgian culture and, it was widely believed, had decided to kill him. There is some evidence that Stalin's friend Sergo Ordzhonikidze organized or took part in the assassination.