Earlier in his career, Andropov served as the Soviet ambassador to Hungary from 1954 to 1957. During this period, he took part in the suppression of the 1956 Hungarian Uprising. Later under the leadership of Leonid Brezhnev, he was appointed chairman of the KGB on 10 May 1967. After Brezhnev suffered a stroke in 1975 that significantly impaired his ability to govern, Andropov began to increasingly dictate Soviet policymaking alongside Foreign Minister Andrei Gromyko, Defense Minister Andrei Grechko and Grechko's successor, Marshal Dmitry Ustinov.
Earlier in his career Andropov served as the Soviet ambassador to Hungary from 1954 to 1957. During this period, he took part in the suppression of the 1956 Hungarian Uprising. Later under the leadership of Leonid Brezhnev, he was appointed chairman of the KGB on 10 May 1967. After Brezhnev suffered a stroke in 1975 that significantly impaired his ability to govern Andropov began to increasingly dictate Soviet policymaking alongside Foreign Minister Andrei Gromyko, Defense Minister Andrei Grechko and Grechko's successor, Marshal Dmitry Ustinov.