The periodization of history and the definition of the framework of Antiquity and the Middle Ages were questions open for scientific discussion at the turn of the 19th-20th centuries, when the Russian school of ancient and medieval studies was actively developing in Russia and especially in St. Petersburg. The concept of I. M. Grevs was that the Roman Empire marked the beginning of Late Antiquity with its special economic structure in the form of large land ownership, but this period ended with the onset of the era of barbarian kingdoms. I. M. Grevs separated the Roman Empire from the period of classical Antiquity and at the same time showed its difference from the way of the early Middle Ages. In his courses on general history, read after I. M. Grevs, N. I. Kareev described the ancient universal monarchies, which sought to extend their power to the limits of the ecumene and unite the various traditions of organizing power. It should be concluded that N. I. Kareev supplemented the periodization proposed by I. M. Grevs, finding in the Ancient world the same turning point in the form of the Hellenistic monarchy, similar to that found in Late Antiquity by I. M. Grevs.