Although this miniature is unsigned, a kind visitor to the website has advised the artist is Hans Joachim Brunschweiler (1770-1853). He was born in Erlen, Switzerland and died there in 1853. He appears to have married Anna (born 29 Jul 1781-?) on 25 Sep 1802, at the Evangelisch, Sulgen, Thurgau, Switzerland.
Hans Joachim Brunschweiler was a self-taught miniaturist. In 1816 he painted a portrait of the Princess of Fuerstenberg, later those of the Prince of Hohenlohe, the King of Wuerttemberg and the Grand Duchess of Baden. He worked about 1820 in St. Gall, about 1830 In Frauenfeld, later returning to his native town Erlen. He almost never signed his miniatures.
Schidlof observes "Brunschweiler painted with a lot of gum which made his colours quite fresh, the execution is finical, the lines often hard. Frequently his miniatures have the effect of pigments on porcelain and the persons represented have flushed cheeks. It seems amazing that this rather average artist obtained so much success and painted many important people."
The sitter is unknown, but the miniature probably dates from around 1825. 1159