This article is devoted to a reconstruction of discussions on pre-industrial cycles based on an analysis of a wide range of unknown and little-known historiographical sources and archival materials. Kondratiev long cycle is generally treated as a phenomenon of a modern world economy. However, the existence of major cycles before the Industrial Revolution does not contradict the theoretical views of Nikolai Kondratiev, the founder of the long-waves theory. The key question, therefore, we are trying to answer is why are major cycles not associated with a pre-industrial economy? The answer to this question can be found by examining the reception of Kondratiev's ideas in the Western scientific community. The fact is that 1935's publication of an abridged translation of Kondratiev's article ultimately led to active discussions, but were based on extremely fragmented ideas about his scientific heritage. Only much later, in the 19801990s, Kondratiev's major works were reissued and translated into foreign languages. When we consult these works, we find he never used concepts such as `first long wave' and `second long wave,' unlike the translator of his famous article. Moreover, we have discovered archival documents, which indicate that the problem of the existence of long cycles before the Industrial Revolution had attracted Kondratiev's interest. Why didn't he make publications about this issue? Most likely, the answer can be found in the political context of the discussions in the USSR. His conception contradicted the notions of the inevitable and swift collapse of world capitalism - such ideas were especially typical for representatives and supporters of the Left-wing Opposition. Therefore, Kondratiev's position could not but draw the attention of well-known Marxists. It is unlikely that Kondratiev could afford to expand the time frame of his research. We also note that there is a strong presumption that after 1930, when Kondratiev was arrested, Soviet scientists had not conducted any research on long cycles. In the present study, the correctness of this claim is challenged. We have at our disposal a number of historiographical sources, which indicate that Soviet scientists cared about the existence of long cycles in the pre-industrial period. Soviet historians had analyzed foreign literature on long waves before Soviet economists did. Therefore, the historians pioneered the study of time-series data. Under the influence of French historiography, Soviet historians also turned to empirical studies on pre-industrial cycles.