Preface -- An Empirical Study of the Politburo -- The Data Base -- The Qualitative Politburo Environment -- The Lenin-Stalin Years -- Lenin's Politburo (1917-21) -- The Stalin Era (1922-52) -- A New Deal in Soviet Politics -- The Khrushchev Era (1953-63) -- The Brezhnev Era (1964-81) -- The Andropov-Chernenko Interregnum (1982-84) -- Gorbachev and the Future -- The Dawn of a Grobachev Era? (1985-??) -- A New "Time of Troubles" -- Appendix: Chronology of Politburo Members