On July 2 1815, Admiral Sir Edward Thornborough writes to William Mounsey, the Captain of the Feurieuse, with secret orders in case Napoleon is captured.
Sir – In reference to my orders to you of yesterday’s date relative to Napoleon Buonaparte I am to acquaint you a proposition has reached His Majesty’s Government from the present rulers of France demanding a passport and safe conduct for Buonaparte and his Family to proceed to America. In this proposition His Majesty’s Government have returned a negative answer and it now seems more probable than ever that Buonaparte will endeavor to effect his Escape either to England or what is more likely to America.
I have therefore to desire that if you should be fortunate as to intercept Buonaparte you will transfer him and his Family to His Majesty’s Ship you Command and [there] There keeping him in careful custody, you are to return to the nearest port of England with all possible Expedition.
You are not to permit any communication whatsoever with the shore and you are to observe that you will be held responsible for keeping the whole transaction a profound Secret until the pleasure of the Lords Commissioners of the Admiralty shall be received.
Should you, having Buonaparte on Board, arrive at a port in which there is a Flag Officer you are to send and acquaint him with the circumstance, strictly charging the Officer sent on shore with your Letter not to divulge its contents; if there should however be no Flag Officer at the Port at which you may arrive you are to send a Letter by Express to the Secretary of the Admiralty with a strict injunction [of] (end page 2 ) of Secrecy to the Officer who may be the Bearer of it.
Instead of the ten days mentioned in my said Order of yesterday you are to remain out until you receive further directions from me or have certain information that Buonaparte has been taken.
I am Your most Obedient humble Servant
Edw’d Thornbrough Admiral
PS You are to communicate The contents of this Letter To the Commander of the Brig under your Orders As well as to the Captains & Commanders of such of Her Majesty’s Cruizers you May fall in with.