The fundamental work of the outstanding Russian botanist, sinologist, historian, historiographer, source scholar, geographer and traveler Emilia Vasilyevich Bretschneider (1833-1901) is devoted to the history and geography of Central Asia and East Turkestan in the Middle Ages. This book is a wonderful monument of Russian oriental studies, it is on a par with the works of N.Ya. Bichurin (Iakinf), P.I. Kafarov (Palladium), V.P. Vasilyeva, B.Ya. Vladimirtsova, V.V. Bartold, G.E. Grum-Grzhimailo and other scientists of this circle. And if the translations of the author's Chinese, Mongolian and Persian written sources are now outdated, then his historical and geographical comments on them continue to be valuable. This study is being published in Russian for the first time.