Collector of Russian lands

The collector of Russian lands, also known as the gathering of the Russian lands (собирание Русской земли), is a historical concept and the study of the expansionist policy of the Grand Duchy of Moscow and the Grand Duchy of Lithuania. The term could be found in works of several historians such as Dmitry Ilovaysky ("History of Ruthenia: Muscovy-Lithuanian period or Collectors of Russia (Rus)"), Kazimierz Waliszewski ("First Romanovs", "Ivan Grozny") and many others. In the historical studies of Russia, the concept justifies the liquidation of political (feudal) fragmentation in the post Golden Horde period.