Peter Rübke and his stepchildren (Maria Louisa, Johann Jakob, and Anna Dorothea Krug) settled in the Volga German colony of Kratzke on 7 August 1766. They are recorded there on the 1767 census in Household No. 9. Peter did not have any surving male descendants, and this surname does not continue among the Volga German colonies.
The 1767 census records that he was from the city of Bremen.
- Mai, Brent Alan. 1798 Census of the German Colonies along the Volga (Lincoln, NE: American Historical Society of Germans from Russia, 1999): Kr03.
- Pleve, Igor. Einwanderung in das Wolgagebiet 1764-1767 Band 2 (Goettingen: Der Göttinger Arbeitskreis; 2001): 451.