Abstract
It is important to study the historical and geographical issues of the Caspian Sea, whose name underwent various changes in different periods of history due to the historical and political situation of that time. The article is written based on Russian, Kazakhstan and foreign scientific works. The purpose and objectives of the research is to study the historical significance of the expeditions organized by Peter I for the purpose of research and development of the Caspian Sea basin at the beginning of the 18th century in the collection of scientific data about the sea. Analyzing data on the history of the sea, the name of the sea; Conducting scientific analysis of the records of Russian travelers and scientists found in archive funds on the historical, geographical and economic features of the sea. The Caspian Sea and its historical and geographical issues have been the subject of historical research of many travelers, historians, geographers and scientists since ancient times. The authors make scientific conclusions by systematizing a lot of cartographic materials and data written on this issue, focusing on the expeditions organized along the Caspian Sea during the period of Peter I.