The paper aims to provide insight into the content of the diplomatic documents from the “Persian” fund of the Russian State Archive of Ancient Acts, which reveals the role of the Crimean prince Şahin Geray in relations between Safavid Iran and the Russian Tsardom at the turn of the 1620s and 1630s. A detailed source examination is given to a group of nineteen texts dated 1630. This set consists of letters in Turki and Farsi, as well as their Russian translations and a preface by the administrators of Astrakhan. The addressees of correspondence were Astrakhan and Terek voivods and the governor of the non-Russian population of the Terky Sholokh Cherkassky. The senders were Shah Safi I, Şahin Geray, beglerbeg of Shirvan Qazaq Khan and shamkhal of Tarki Ildar. The materials analyzed reflect the attempts of the aforementioned political emigrant, with the support of the Shahs Abbas the Great and then Safi I to obtain diplomatic and military assistance from Moscow and the local Russian authorities of the Ciscaucasia in reconquering Crimea. The authors reveal the details of the plan of Şahin Geray and the reasons for the Russian negative stance on any combinations involving the former Crimean qalga. The scholars conclude that supporting of the political figure unacceptable for the Romanov monarchy by Shah has become one of the significant factors holding back the development of Russian-Persian relations in the period under review. In the appendix one can find a Turki text of the firman by Safi I to voivods, as well as its contemporary and recent translations into Russian.