Over a period spanning 20 party congresses between Lenin and Gorbachev, the destiny of the Soviet Union and its peoples was basically decided by the 130 individuals who sat on the Politburo. For seven decades the Politburo was the most powerful organ in the Soviet political system, because its members were the top office-holders in party, government and state institutions that had been imbued with the bolshevik tradition of concentration of power. The Politburo’s power showed itself in the fact that through other institutions, it could manipulate its political, economic and social environment. Concealment, fear, manipulation, scheming and stringpulling were its instruments. After dealing with the history of this institution, the reader is now invited to take a closer look at its central place in the Soviet power structure and at the way in which it operated. Inevitably, we will have to start with the formal rules and procedures that governed the relations between the Politburo and other institutions.