The question of dating an urban settlement, if its date has no clear or specific written confirmation, is always very problematic and complicated. Its solution requires the use of the widest possible range of data. This research is presented in
a block of articles that attempt to cover the source-historiographical study of the existence of the second Kostroma Kremlin, including the latest archaeological data from 2016-2017 on the territory of the Old city of the second Kostroma Kremlin. The study raises questions about the conditions, specifics and dating of the foundation of the first and second Kostroma Kremlins, their nature of development, the conditions for obtaining the icon Our Lady of Saint Theodore in Kostroma and its storage location in both Kremlins. The question of the place, time and conditions of the construction of the Assumption Cathedral is considered separately, since only research on the conditions and dating of its construction can shed light on the date of the foundation of the Old city of the second Kostroma Kremlin. Article 2 continues this block of research, which refers us to the time and conditions of building the Dormition Cathedral.