The monograph of the famous historian of the Russian fleet is devoted to the topic of the development of the Caspian by Russia, starting from the time of Kievan Rus. The author of the article is an interesting selection of evidence of the appearance of Rus in this region. Noteworthy is the analysis of the evolution of trade relations between the Moscow kingdom and Persia over several centuries, as well as the conflict between the military-economic interests of Russia and England, dating back to the era of Ivan the Terrible. The progress of the scientific study of Caspian and its coast by Russian sailors, hydrographs and cartographers is reflected in detail. For the first time, the significance of the Caspian flotilla in support of the campaigns of the Russian army to conquer the eastern coast of Caspian and the states of Central Asia in the second half of the 19th century was revealed in detail. Particular attention is paid to the role of S.0. Makarov in organizing the supply of troops of General M.D. Skobelev and the construction of a railway in the sands of Turkestan.