How old was Mikhail Gorbachev when he ecame a member of the Politburo ?
In 1980 , the average Politburo member was 70 years old ( as opposed to 55 in 1952 and 61 in 1964 ) , and by 1982 , Brezhnev 's Minister of Foreign Affairs Andrei Gromyko , his Minister of Defense Dmitriy Ustinov and his Premier Nikolai Tikhonov were all in their mid-to - late seventies .