Introduction. The paper deals with one of the aspects of the economic policy of the Russian Empire in its Peri-Caspian provinces, annexed as a result of the Persian campaign of Peter the Great. The aim of the study is to analyze the main income items of the imperial treasury based on the materials of the Derbent garrison of the Lower Corps, to establish the share of income received in Derbent in the structure of all income of the Lower Corps. Tasks: to characterize all income sources of the Derbent garrison, to show the activities of commandants and other military leaders in streamlining the income structure, in replenishing the imperial treasury, to consider the interaction of the Russian authorities of Derbent with foreign merchants and domestic salesmen, to describe the daily life of the garrison in Derbent. Methods and materials. The study is based on the archival documents from the Central State Archive of the Republic of Dagestan, mainly from fond 18 “Derbent commandant”, most of which are introduced for the first time. Additionally, the modern achievements of historical science on the subject have also been considered. The methods of the study are the following: the principles of historicism and objectivity, an integrated approach, a systematic method, methods of criticizing historical sources. Based on the analysis of the documentary material, it was possible to restore the picture characterizing the everyday life of the military personnel in the Derbent garrison of the imperial army. Analysis. The fiscal activity inside the Derbend garrison was controlled by the commandant, whose duties, in addition to military-political ones, included collecting taxes and fees, reporting on them to the central imperial authorities and administration. The amount of incomes for the reporting periods are described in detail, the role of Derbent customs in replenishing the Russian treasury and the trade of the Derbent administration with foreign merchants are shown. Considerable emphasis is put to the activities of the military leadership of the Lower Corps and the Derbent Garrison, directly aimed at increasing financial revenues of the imperial treasury. Results. As a result of the study, valuable archival documents were introduced into the scientific circulation, reconstructing the daily life of the Derbent garrison, the main sources of income in this garrison were identified. It was established that the revenues of the imperial treasury in the Derbent garrison were clearly differentiated and structured. Customs duties accounted for more than half of the revenue in Derbent, while the other part was collected from the sale of wine, vegetables, oil, and court fines. The “Persian” incomes were spent on salaries and remuneration to the Caucasian political elite loyal to the Russians, to keep the amanates (hostages) from Caucasian rulers, to pay wages to masters for the repair and reconstruction of fortresses, to maintain postal communications, etc. Despite the emperor’s ambitious plans for the economic development of the “newly conquered” former Persian provinces, many of the projects he started were not completed and scraped after his death. A pressing example of it would be the abandonment of the construction of the Derbent port enclosed from sea storms.