Rudolph Kretz, a craftsman (Handwerker), and his wife Anna Dorothea settled in the Volga German colony of Schäfer on 1 August 1766. They are recorded there on the 1767 census in Household No. 17.
The 1767 census records that Rudolph Kretz came from the German village of Nieste [?] in the Darmstadt region.
There are no known surviving male descendants of this family among the Volga German colonies.
- Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 4 (Göttingen: Göttinger Arbeitskreis, 2008): 93.