1To Thomas Jefferson from Rodolph Vall-Travers, 18 April 1793 (Jefferson Papers)
...the Emperor’s beloved brother Prince Charles, Archduke of Austria—that might pave the way for...
2Isaac A. Coles to Thomas Jefferson, 26 July 1809 (Jefferson Papers)
Austria; Charles, archduke of Austria [index entry] Charles, archduke of Austria [index entry]