Nikolay Pavlovich Antsiferov (1889–1958) is an outstanding historian and literary critic, author of classic works on the history of St. Petersburg. Before the publication of this edition, Antsiferov’s epistolary heritage had not been published. Meanwhile, the diversity of his recipients and a wide circle of acquaintances, from Vladimir Vernadsky to Boris Eikhenbaum and Marina Yudina, make the scientist’s correspondence a valuable source of knowledge about Russian culture of the 20th century. A special layer in it is a collection of letters sent to family and friends from the Gulag (1929–1933, 1938–1939), a unique human document from the era of total dehumanization of society. Collected by addressees, epistolary complexes turn into special stylistic and figurative-plot unities, and together they are a literary monument reflecting the realities of the time, the history of the fate of a witness to the tragic events of the twentieth century.