Tens of millions were swept up in the gulag, shipped off to exile, forced labor, and often death. The victims included ethnic minorities and the intelligentsia, but also, less well known, the so-called kulaks.

Alexander Solzhenitsyn, who documented the Soviet penal system in “The Gulag Archipelago,” wrote of the nearly 2 million kulaks deported between 1930 and 1931: “This wave poured forth, sank down into the permafrost, and even our most active minds recall hardly a thing about it.”

Who were the kulaks? “There are no national monuments to the kulaks,” Lynne Viola writes in “The Unknown Gulag” (Oxford University Press, 352 pages, $30). “Their graves lie scattered and unmarked across the vast expanses of the former Soviet Union, the death toll through the 1930s roughly half a million people.”

“Kulak” was an amorphous term, literally a “fist,” that variously denoted a rural capitalist, village exploiter, or “tightfisted” peasant. Because of their pasts or their politics, or simply to round out quotas, kulaks were packed into train cars in the middle of the night and deposited in an inhospitable land to work in “special settlements.”

In the most remote regions of the Ural Mountains, the Northern Territory, Siberia, and Kazakhstan, these hardworking peasants were to be “reforged” and re-educated as part of the campaign to “liquidate the kulak as a class.” As Ms. Viola writes, “The kulak had become the most dangerous foe in the Communist Party’s ever-expanding pantheon of enemies.”

In this meticulously detailed book, Ms. Viola, a professor of history at the University of Toronto and the author of “Peasant Rebels Under Stalin,” describes what she calls “the other archipelago” of Josef Stalin’s special settlements, which laid the foundation for the gulag. The idea for the settlements arose in the rush to complete the First Five-Year Plan (1928–32), the colossal undertaking that was intended to transform the Soviet Union into a modern nation from an agrarian society.

In 1930, the acting head of the secret police, or OGPU, Genrikh Yagoda, laid out his idea for a new Soviet penal system, to be composed of “colonization villages.” These villages would serve “to colonize the north in the fastest possible tempos,” Yagoda wrote, and ensure the exploitation of the Soviet Union’s immense natural and mineral resources. Not only would the new special settlements be less costly to maintain for the authorities than the existing system, Yagoda promised, they would soon become self-sufficient and benefit the economy.

Many escaped the special settlements, many died of hunger and overwork in the forests or mines of the taiga, but few were “reforged.” The policy was “an unmitigated disaster” that, far from bringing the state any economic benefit or transforming a “class enemy” into a Soviet citizen, only brought about the special settlers’ “untimely death.”

Ms. Viola points out that the peasantry served as a kind of “internal colony” for the Soviet Union, paying a “tribute” to Stalin through collectivization, taxation, and forced labor to finance the empire’s industrialization. Special settlement planning, conducted always “na khodu,” or on the fly, “was socialist realism in another context,” she writes. “It represented an ‘imagined future’ … superimposed on the present-day realities of the Soviet hinterlands. It was planning grafted onto chaos, a projection of communist visions of order onto the disorder of a reality of the regime’s own making.”

The underlying reason for this chaos, Ms. Viola writes, was the fundamental weakness of the Stalinist state, which in the 1930s “operated within the confines of widespread backwardness.” State structures were weakly developed outside the center and major cities, and the Communist Party presence was negligible in the countryside. Under such circumstances, Stalin resorted to repression and constant emergencies to exert control.

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As the “resettlement” of the kulaks continued, millions of other “undesirables” joined them in internal exile. Yagoda’s “grandiose plan” to cleanse Moscow and Leningrad of “socially dangerous elements” in 1933 forms the backbone of the French historian Nicolas Werth’s absorbing new book, “Cannibal Island” (Princeton University Press, 248 pages, $24.95). What transpired on the island of Nazino, 500 miles north of the Siberian city of Tomsk, is yet another chapter of what Mr. Werth calls the “hidden” gulag.

Stalin trumpeted the “liquidation of the exploiting classes” in a speech to the Central Committee in January 1933, but warned that the opposition had not disappeared, just taken another form: Now the chief threat to the construction of socialism would be criminality and social deviance.

As famine swept through the Volga region, the North Caucasus, and Ukraine in late 1932, peasants flocked to the cities to find food. To “purify” and cleanse Moscow and Leningrad and other strategic cities, an idea first proposed by Felix Dzerzhinsky in 1926, Yagoda announced an internal passport system. Passports would be required of all residents of strategic cities, and those without passports would be required to relocate within 10 days.

As a result of police roundups and constant passport checks, the prisons were overflowing and needed “decongesting.” To fulfill his “grandiose plan,” Yagoda resettled 1 million such criminal and déclassé “elements” in 1933–34 in remote regions to bring into production 2.5 million acres of virgin land. But the “grandiose plan” was again carried out on the fly. During passport checks, Mr. Werth writes, “The police not only paid no attention to documents, attestations, certificates, or union or political party cards when they were presented, but in addition frequently confiscated them,” their immediate goal being “to fill the convoys and to reports results in numbers.”

Mr. Werth starkly recounts the stories of a number of deportees, including V. Novolozhilov, described as a “Muscovite, stocker in the Kompressor factory, three-time award winner. Wife and child duly registered in Moscow. After work, he was preparing to go to the movies with his wife. While she was getting ready, he went out to buy cigarettes. Rounded up and deported.”

After detailing the lead-up to the deportation of the “socially harmful elements” and the political situation surrounding it, Mr. Werth zeroes in on the Nazino affair to illustrate the policy’s devastating effect. The 6,000 city dwellers of that Siberian island had been rounded up before Labor Day, May 1, 1933, in a “cleansing” of Moscow and Leningrad. Two weeks later, they arrived at a transit camp in Tomsk, with no possessions, emaciated, some suffering from typhus, some barely clothed.

In short order they were sent by riverboat to a small island near the confluence of the Ob and the Nazina rivers, across from a village. From this island, the exiles would be taken to their “final place of settlement.” For food, 20 tons of flour was dumped on the ground, which immediately became covered with snow in an ensuing storm. In the weeks that followed, Mr. Werth writes, two-thirds of the deportees died of hunger, exhaustion, and disease, as the poorly trained guards broke into gunfire at the slightest hesitation amid reports of cannibalism and looting for gold crowns. Those deportees that remained were taken to similarly inhospitable spots, where yet more died.

Yagoda, the head of the secret police, now called the NKVD, was arrested in March 1937 and executed in 1938. Ms. Viola suggests that the failed special settlements played no small part in his demise. But the deportations did not abate with his fall, picking up speed during Stalin’s “Great Terror” of 1937–38. In those two years, Ms. Viola writes, “the NKVD arrested 1,575,259 people, leading to 1,344,923 convictions and 681,692 executions; by early 1939 well over 2 million people were imprisoned within the labor camps, colonies, and prisons.”

Only after Stalin’s death in 1954 did the Central Committee of the Communist Party lift all restrictions on “former kulaks exiled in 1929–33 from the districts of wholesale collectivization.” But the kulaks elicited no mention in Nikita Khrushchev’s secret speech, and they were not officially exonerated until 1991, when President Yeltsin signed a law absolving them and ascribing the special settlements “to the arbitrariness of a totalitarian government.”

Ms. Mercer last wrote for these pages on Anna Politkovskaya.