The attribution is probably facetious.
The letter is headed: 'To the ambassador of France at Rome'.
Signed and dated at foot: Richelieu. Paris, 31st, Nov. 1638.
Printed in two columns.
If read across the columns, the text appears to be a letter of recommendation for a Mons. Campy; if the first column alone is read, it proves to be the opposite.
Reproduction of original from Bodleian Library (Oxford).
Electronic reproduction. Farmington Hills, Mich. : Cengage Gale, 2009. Available via the World Wide Web. Access limited by licensing agreements.