The "palace revolution" on October (1964) Plenum of the CPSU removed Nikita Khrushev, a party leader. This happened for the first time in 50-year history of the Communist Party.
November (1964) Plenum of the CPSU Central Commettee approved nomination of a number of leaders, who had played a noticeable role in those events: L.Brezhnev, the first secretary of the CPSU Central Committee, A.Kosygin, the chairman of the USSR Council of Ministers and M.Suslov, the Presidium of the Supreme Soviet member in charge of ideology.
The peculiarity of the party and state system of the USSR was that it was impossible to act without a clearly shaped leader. That place was occupied by Leonid Brezhnev. On XXIII CPSU Congress he was elected as General Secretary of the CPSU Central Committee (that post was called "First Secretary" before). He remained at that post up to his death in 1982. Yury Andropov followed him, then in 1984 Konstantin Chernenko came to power (died in March, 1985).
In early 70-s Brezhnev managed to gain a foothold, when, participating on most international conferences of the East and West, he occupied Alex Cosigin's place. By and by all the key posts were occupied by workers whom Brezhnev had known well enough on his activity in Moldavia and the Ukraine. The situation was controlled by means of well-known already in Stalin's period "personnel control level" that always enabled the party apparatus to reach their purpose.
In 1965-1970 the leadership carried out a rather vast replacement of local manpower, that had been administered to their posts in Khrutshev's time. That new personnel constituted the skeleton of all Brezhnev's administration, up to the 80-s.
For the first time in history that was a period of the party and state nomenklature's comparatively stabilised existence, without traditional mass comb-outs. That was a period of a high level of protection, when for the first time the nomenclature came close to practical owing power, managed to concentrate in their hands controls over the riches of the country.
All-in-all 1965-1984 was a period of a comparatively slow evolution of party and federal power foundations, within the borders of the current regime. This time is traditionally called "stagnation", or "stagnation period". As in former time, the Supreme Soviet was the ultimate federal body. It consisted of the Soviet of Union and the Soviet of Nationalities. Elections were to be once in five years; Sessions were gathered yearly.
The Council of Ministers was the ultimate executive body. In 1978 a Presidium appeared in the Council of Ministers, because of quantitative membership growth and complexity in management. In 1964 A.N.Kosygin was appointed the Chairman of the Soviet of Ministers. He remained there up to his death in 1980. Since 1980 through 1985 the post of the Chairman was occupied by N.Tikhonov.
A speciality of the time: intensive swelling of the apparatus. New ministries and departments appeared almost each year. Due to the management apparatus overgrowth it became the most numerous one in the world (apart from China). By the mid-80-s 18 mln employees worked there, which was 1/7 of the whole able-to-work population of the USSR.
Problems connected with how to feed such a massive apparatus began to appear. After Brezhnev's death Yury Andropov came to power. He tried to make the bureaucratic apparatus more effective by means of barely structural changes, strengthening repressive organs, first of all KGB. He couldn't attain the purpose though, since the party and state apparatus didn't want to part with their benefits. Yury Andropov died in February, 1984. His comb-out operation remained unfinished.
Stabilisation of the main political and state institutions by the mid-70 had its reflection in new 1977 "Brezhnev's" Constitution of the USSR. In 1962 an constitutional commission was established. After Khrushev's removal soviet leadership rejected the idea of construction communism in the USSR by 1980. There appeared a new definition: "Well-developed socialism".
In article 6 of the 1977 Constitution monopolistic leading role of the CPSU was formally legalised. The CPSU was understood as "directing and managing force of the Soviet society". Promotion in any sphere was possible only providing the person had been an active CPSU member. This was the basic reason why in 1965-1985 the party quantitative membership grew like leavened dough.
In "stagnation" period four CPSU Congresses were held: XXIII, XXIV, XXV and XXVI ones.