Star on old fellas chest

Wondering what the star is on the breast of these old chaps coats or uniforms? Two of the portraits are of a Prussian king. One purports to be Russian, and one is unidentified. Other examples can be found but I am still unsure what it represents? I’d guess a military symbol but if the sitters hail from different countries I’m not so sure.

 

Order of St. Anne?

 

Yes, they're breast stars. Frederick II wore the Order of the Black Eagle. You can read more about it here:

https://edsimoneit.blog/2019/12/07/...ecoration-frederick-ever-wore-on-his-uniform/

Debora

 

Nikolay Bantysh-Kamensky received three orders: the Order of St. Anna, the Order of St. Vladimir and the Order of St. John of Jerusalem.

https://en.wikipedia.org/wiki/Order_of_Saint_Anna

https://en.wikipedia.org/wiki/Order_of_Saint_Vladimir

https://www.ghlilley.com.au/product...RVuDAwrb4h_Ggs0KUogWPOPZDhAv8-mVBVZ6l--k6dwGg

Debora