Readers are invited to the first Russian translation of the medieval Arabic treatise on navigation by Sulaiman al-Mahri “al-'Umda al-mahriyya fi dabt al-'ulum al-bahriyya”, made by the Leningrad orientalist T.A. Shumovsky, based on a comparison of all surviving lists of works back in the 70s of the twentieth century, simultaneously with the preparation of the publication of a nautical treatise by al-Mahri’s senior contemporary, Ahmad ibn Majid. For a number of reasons, al-Makhri’s work did not see the light of day. Only the Book of Benefits by Ahmad ibn Majid was published. This publication was prepared for publication by A. S. Matveev, a research fellow at the Faculty of Oriental Studies at St. Petersburg State University, and contains a facsimile of the most ancient, Paris manuscript of al-Makhri’s work (based on the edition of the French orientalist G. Ferrand), with a detailed textual commentary by T. A. Shumovsky. The book is provided with a detailed English summary in order to make it accessible to Western readers. The book is intended for orientalists and specialists in the history of navigation and geography, as well as for anyone interested in the history of maritime affairs and the culture of the Muslim East.