What age did Mikhail Gorbachev become a member of the Politburo ?
Andrei Gromyko , one of the oldest and widely respected Politburo members , nominated Gorbachev for the position of General Secretary of CPSU , both at the March 11 meeting of Politburo and subsequently at the March 1985 Plenum ( meeting ) of the Central Committee of the CPSU .