This paper deals with the prominent participants of the February Revolution in 1917 who came to live in Belgrade, throughout the research of the primary historical source, Card Register of the Citizens of Belgrade and Zemun 1924 - 1950. Special attention was paid to the analysis of the structure of data in the cards, especially those concerning the new perspectives of the researches of the Russian emigration. Presented at Solzhenitsyn House for the Russian Diaspora, Moscow, October 27th, 2017.