Complex sentence: When Brezhnev died in 1982, he was succeded by Yuri Andropov, who died quickly after taking power, was in turn succeeded by Konstantin Chernenko, who ruled for no more than 13 months.
Split into simpler sentences: When Brezhnev died in 1982, he was succeded by Yuri Andropov, who died quickly after taking power. Andropov was succeeded by Konstantin Chernenko, who ruled for no more than 13 months.