Family #1 in the 1775 Grimm census.
Christian Grimm was born about 1747 in Germany to Gottfried Grimm and an unnamed mother. He immigrated with his family to Russia in 1766-1767. By the time of the 1775 census, they had settled in Grimm.
1775 Grimm Census 
This census reveals that Anna Katharina, Gottfried's wife at the time of this census, had a three year old child with her previous husband. This means that she cannot be the mother of any of Gottfried's children. The most likely scenario is that Gottfried's first wife and Anna Katharina's first husband did not survive the journey to the Volga River, and that the couple married between 1766 and 1767, either in Oranienbaum, Russia, or shortly after they arrived in Grimm.
According to a note in the Appendix of the 1798 Grimm census, Christian Grimm left Grimm after paying his debts in 1787 when he was 40 years old.  The 1798 census for all the German colonies along the Volga does not list a Christian Grimm as living in any colony.  It's not clear if he moved to a Russian town or perhaps to the southern villages in the Black Sea area, although a review of http://www.blackseagr.org/ shows no one with that name born around 1747. There was a Jakob Grimm who lived in Norka, and it's possible the two were brothers, since there only appears to be one Grimm family who immigrated to the Volga River colonies in Russia.  If Christian and Jakob Grimm immigrated to Norka together in 1787, then Christian either left Norka before 1798 or he was deceased.
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