conventionDeclaration detailLevel http://ica-atom.org/doc/RS-2#5.4 thepeerage.com person Castellain, Hermenegild Augustus Maria (1770-1849), diplomat conventionDeclaration 27 January 1770 - 28 April 1849 Portrait print of Hermenegild Castellain Letter from Hermenegild Castellain to Jean-Sylvain Van de Weyer Letter from Nicaise de Keyser to Monsieur H. Castellain