EN
Common past of Belarusians, Poles and Russians create the history of the Eastern lands of the former Polish-Lithuanian Commonwealth. Historical biographical dictionaries play an important role in studies of the historians from these lands. The article discusses 4 Belarusian, 3 Polish and 2 Russian biographical dictionaries describing important people from the 19th century and the beginning of the 20th century. In this article, two encyclopedias devoted to the Russian State Duma and the State Council reformed after 1906 were also assessed. The whole article shows the meaning of the historical biography in the progress of the scientific research over the past ages.