I have come across a Google Books footnote reference in a Polish book called Legiony Polskie, 1794-1807 by Jan Pachoński. It refers to an Archive called AE, followed by things like AE, Memoires/Pologne/Toscane etc. Then comes rkps (Polish for manuscript) number, then s. (strona - Polish for page) number. There are also some archives listed as AS with Italian cities, which I take to be Italian 'Archivo di Stado', which are Italian state archives.
Does anyone have Panchonski's books? Or any ideas about the AE ref, given the manscript/page numbers? I am thinking it is a French archive.
Thanks for that confirmation, Ian,
Looking at the English language version of "Poland's Caribbean tragedy : a study of Polish legions in the Haitian war of independence, 1802-1803" by Jan Pachoński, the abbreviation "AE" in the footnotes stands for "Archives (du Ministère des Affaires Etrangères, Paris). This work can be borrowed from Internet Archive.
That would be possible as it refers to the various states after AE. Thanks.
Possibly Archives des Affaires étrangères, Paris