The aim of the article is to update the scientific heritage of the famous Slavist, professor of St. Peters-burg University and a prominent representative of late Slavophilism V.I. Lamansky (1833–1914). His biography is insufficiently studied in modern research literature. The article reconstructs based on archival documents Lamansky’s work in the archives of Venice in 1868–1869, which resulted in the publication of an extensive collection of documents and studies on the history of relations of the Ve-netian Republic with the Greeks and Slavs during its heyday (16th – early 18th century)—“State Secrets of Venice” (1884). Lamansky himself considered “State Secrets of Venice” his main merit to science. Archival materials allow us to trace the genesis of Lamansky’s historiosophic views, to better under-stand how his civilisation concept, in which the ideas of Slavophiles were developed, was formed. It is stated that the key concept of Lamansky’s work is the idea of a confrontation between the Greco-Slavic and Romano-Germanic cultures in Europe. The preface to “State Secrets of Venice” is one of Lamansky’s main ideological texts, which reflects the Panslavistic ideas that were supported in the Russian academic environment in the last third of the 19th century. As a result, the study provides a better understanding of the ideology of late Slavophilism as a theory which, in Lamansky’s works, claims the status of a scientific programme in the humanities and social sciences.