Who is Iosif Vissarionovich Stalin from The Gulag Archipelago, 1918-1956 and what is their importance?

The General Secretary of the Communist Party of the Soviet Union from 1922, the Georgian-born Stalin is the major point of focus for Solzhenitsyn's contempt for the cruel, arbitrary Soviet system. Solzhenitsyn rarely names the dictator, who gradually eliminates rivals after Vladimir Lenin's death in 1924, preferring instead to speak obliquely, using various terms of endearment applied to him by sycophants during his lifetime. He does not explain while, when pleading for his life in 1937, fallen Politburo member Bukharin writes letters to "Koba," using Stalin's party name from the old days. Solzhenitsyn also speaks obliquely of Stalin as an "abuser of the cult," the deprecatory term Khrushchev uses while revealing Stalin's crimes after his death in 1953.