Mary, Queen of Scots spent almost 20 years in captivity. She was held in various locations across Britain from 1568 until her execution on February 8 1587. As I explain in my new book, Captive Queen: The Decrypted History of Mary, Queen of Scots, during this period she relied upon letters to maintain her support back in Scotland, encourage international allies to join her cause and foster allegiances in England.
Mary was aware that her letters were routinely read by her jailers and passed on to be scrutinised by Elizabeth I’s closest advisers, notably William Cecil. At times, she was forced to rely on clandestine techniques, including writing in invisible ink. She wrote that “although such artifices be very hazardous and vulgar, they will serve me in extreme necessity”.
Less technical means of conveying correspondence covertly also proved useful. Letters were regularly passed surreptitiously in clothing. They could be slipped under the sleeves of ladies’ gowns, sewn into doublets, or even packed into the heel of a shoe.
