ABSTRACT
The concept of the Grand Duchy's expansion as a conquest that liberated Ruthenian lands from the Golden Horde's rule is most suited to explaining its achievements in the fourteenth and early fifteenth centuries. Less credible would be the application of this concept to the Ruthenian territories in the immediate neighbourhood of Lithuania that fell under its occupation the earliest. Michael Doyle's concept of the "imperial expansion" threshold in the peripheries gives the best description of the political conditions in Kievan Rus'. He uses this concept to describe the internal social processes and conflicts that make a society an object of imperial expansion from outside. In terms of the law of that inter-polity society to which the Kievan Rus' lands belonged, the ascension of Lithuanian dukes to the Ruthenian princes' thrones or tables was akin to a revolution. Individual representatives of the Rurikid lineage and its branches engaged in bloody battles to win one or another district or land.
