This article examines the state of science in Greater Khorasan during the 13th and the first half of the 14th century. Although scientific and cultural life in Transoxiana declined as a result of the Mongol conquest, certain regions of Khorasan witnessed a revival in various branches of scholarship. During this period, scientists created a number of works in various fields of science. In particular, Nasir al-Din Tusi authored more than 200 works in mathematics, geometry, medicine, astronomy, philosophy, logic, astrology, literature, and other disciplines. Geography and literary studies experienced significant development, and numerous works were devoted to the study of rhyme and prosody in the Tajik language. Historiography flourished especially during this period. The majority of historical works of that time were written in Tajik. The development of historical writing was connected, on the one hand, with the historiographical traditions of previous centuries and, on the other hand, with the patronage of the Mongol rulers, who sought to record their military victories in the pages of history through the work of historians. Keywords: science, work, scientist, historian, mathematics, medicine, astronomy, geography, historiography, author