The Secret Messages from Antoine Perrenot de Granvelle to Simon Renard Concerning the Marriage of Mary Tudor

Abstract

The aim of this study is to reveal the secret code used by councillor Antoine Perrenot de Granvelle in his letters to the imperial ambassador Simon Renard to discuss the possible marriage between Prince Philip of Spain and Queen Mary I of England. We will show how three different cipher languages were used by the Spanish Empire in the letters sent to the ambassadors in England between 1553 and 1554. We will then focus on five letters written in French and kept in the Bibliothèque municipale de Besançon. These are partially enciphered and the special cipher which was used reflects the highly secret nature of the message’s content. In this article, we will describe how this cipher works. This will show how the French language was codified in the 16th century to prevent the contents of the message from being intercepted.