The main theme of this outstanding historical work of the 4th century. AD - the acts of Emperor Julian the Apostate, the last pagan on the Roman throne. Ammianus Marcellinus, a Greek by birth, was a contemporary of Julian, served in the army and took part in campaigns under the command of the emperor himself (in 363). Thus, Ammianus’s work represents an eyewitness account, colored with bright artistic colors and imbued with immediate emotionality. Marcellinus's "History" or "Acts" ("Res Gestae") is a continuation of the famous historical work of Tacitus, which was supposed to cover events from 96 to 378. However, the first 13 books are now lost. Only books 14-31 have survived, telling about the events of 353-378. The History of Ammianus Marcellinus is rightfully considered one of the outstanding achievements of Latin literature. The skill of the storyteller, accuracy and truthfulness brought the author the glory of a worthy finisher of the Roman historical tradition, represented by the names of Titus Livy, Tacitus, Suetonius. This publication reproduces the Russian translation by Yu. A. Kulakovsky and A. I. Sonni (Kyiv, 1906-1908, issue 1 -3), newly edited according to the latest Latin editions.