It is well known that for some inscrutable reason, Mother Russia has had (and continues to have) a near monopoly on the production technology of almost perfectly realized mass murderers and delusional tyrants - from Ivan the Terrible to the Gardener of Human Happiness Joseph Stalin. The political repression under Tsars is so well documented not just in non-fiction but also in fiction that one is tempted to dismiss the notorious existential gloom of Russian literature as the by product of Siberian prisoners' and exiles' empty lives in a harsh, frigid, alien land. Indeed, the stench from the powerfully debilitating penal regime (katorga) was foul even during the time of Tsars and such political repression was denounced by the western Europeans of the time who took this as a sign of Russian backwardness. Chekhov himself spent a long time in the Sakhalin Island painting a grim picture of life in prison and exile in Russia.
The inevitable happened then: the Bolsheviks deposed the Tsar to usher in a new era of happiness and prosperity.
The Gulag Archipelago is a two thousand page account of pure horror, a sickeningly detailed diegesis of the sheer terror the Soviet Union unleashed in the name of the dawn of a new mankind, the scale of which staggers imagination and makes Hitler seem only mildly despotic and the notorious Tsars as mere school bullies. Solzhenitsyn's secretly pieced together historical-journalistic masterpiece presents to us essentially the modern history of Russia as seen through the lens of its extensive penal colonies scattered throughout the Soviet territories as archipelagos of concentration camps. (The word 'concentration camp' was invented by the Bolsheviks way back in the '20s, when Hitler had barely begun to capitalize on the Weimar Republic's dire finances, let alone formalized the Final Solution.)
The magnum opus indicts not just the Brilliant Genius of Humanity but lays the ultimate responsibility of the unprecedented Stalinistic terror, deportations of entire nationalities and mass murder of Soviet citizens on an unimaginable scale, at the feet of Lenin himself. Patiently and meticulously, Solzhenitsyn peels away layers upon layers of Red Terror - starting from as early as 1918, continuing well into the civil war ('18-'22) and reaching a sublime perfection under the helmsmanship of the Coryphaeus of Sciences Joseph Stalin and his de-kulakization programs in the late '20s (discounting the several million starving to death as a result of ensuing famines).
Solzhenitsyn's thesis - that it wasn't merely an aberration, that in fact it was ingrained in the philosophies of Bolshevism and Communism itself, that the Soviet state absolutely needed the slave labor (during Stalin's time, about 10% of the Soviet population was in the Gulags - those that died were replaced in fresh purges - a total figure of about 10.5 million!) to industrialize and transition rudely from a poor to a middle income society - was explosive. Even the western democracies' Communist parties, glorifying Lenin and his reading of Marx were left red faced and were forced to reckon the ramification of their leaders' mass murders. It was particularly timely too, since professing an ardent love for Communism in the late '60s and early '70s was even fashionable - thanks to glamorous (and fierce!) public intellectuals like Sartre. (It is still cool to be radical - in no small part due to the efforts of many very gifted intellectuals - from Mayakovksy in the '20s to Sartre in the mid century to Zizek now - one wonders why such fine intelligences succumb to the allure of such repressive ideologies. Not to be left far behind, one should also remember how Heidegger, Reifenstahl etc. endorsed Nazism.) In fact, Solzhenitsyn's work was so well researched (and here we must remember how the Nobelist was working in secret, terrified of being found out and his work destroyed by the KGB) that subsequently, when he was expelled from Soviet Union with his family, all of KGB's efforts to discredit him (they compelled those who knew him to denounce him, tried to manufacture evidence to suggest that he had been an informer in the Gulag etc.) failed miserably.
The Gulag Archipelago (volumes 1-3) are not for the faint-hearted. Although highly recommended, not many can be expected to wade through a thick sludge of gore and entrails for weeks after weeks.