- He had three wives, but nothing is known of his first save that he had one.
On the history of the family, all the way back to the 12th century, see The Von Rosenberg Family Record, vol. 1; and Emigration of the Von Rosenbergs to Texas 1849, ed. and trans. Walter Wupperman et al., which has information taken from the book on the "family Froelich." Alma Julie also refers to a Texas Book of 1949, and the "Froelich Book."
He was a soldier in the Krottingen War (late 1780s or early 1790s). I'm not sure what conflict this is, but I think it refers to Kretinga, so it was pretty local--Kretinga is very close to what was Memel (what is now Klaipėda in Lithuania). Perhaps it was a border conflict, as the region seems to have shifted back and forth among Poles, Russians, and Germans (Prussians).
Note the tangled marriages between his children and the Froelichs. The "Froelich Book" which Alma Julie refers to several times is the source of all of this information.
These notes are from Alma von Rosenberg about a divorce in the family in 1803:
"The inheritor and owner of Eckitten and Raddeilen Estates in 1750 was Sigismund Gustav von Rosenberg. His first son was Otto (1776-1871) who also later inherited and owned Eckitten and Raddeilen, married three times, and was divorced twice! This Otto von Rosenberg was the father of our Pioneer father, Peter Carl Johann von Rosenberg and we had thought there were no divorces in that day, having constantly thought about how such would be handled for Generation Four ! when our next book of the family would be published.
Of Otto's first wife there is no record, no children.
Of the second wife, Maria Wilhelmine von Stempel, there were nine children after a marriage of twelve years and then a divorce in 1802.
Of the third wife, Cathrine von Barkenhagen there were seven children, only one daugher, Emelie, was ever mentioned, and then only one time in the Froelich Book."