An international team of researchers has decoded a set of letters written by Mary Queen of Scots shortly before her execution in 1587. The discoveries are detailed in a recent issue of Cryptology Journal.
The correspondence dates to Mary Stuart’s confinement in England, where she stood as a potential successor to the throne after her Protestant cousin, Queen Elizabeth I. Elizabeth kept Mary imprisoned for nearly two decades to neutralize a perceived threat, a period shaped by religious and political tensions across Europe.
While in captivity, Mary pursued sustained contact with allies and attempted to arrange covert channels to deliver messages while evading adversaries. The team has successfully deciphered fifty-seven letters written in a sophisticated cipher, sent by Mary to the French ambassador in England between 1578 and 1584. For a long time, historians suspected a link between Mary and the French envoy, but those particular letters eluded positive identification until now.
One of the recovered messages expresses gratitude for the recipient’s care and loyalty, asking the addressee to keep up the efforts on Mary’s behalf and to support her planned evacuation, should the circumstances permit. The tone underscores the urgent political calculations behind these communications and the delicate balance of trust and risk involved in a court-in-exile situation.
The newly found correspondence was unveiled on February 8, 1587, marking a historic moment in the archival record. A substantial portion of the letters had been preserved in the National Library of France in Paris, where they are now recognized as crucial pieces of the Marian era. Earlier scholars believed many of these missives to be connected to Italian sources, illustrating how the historical narrative can shift with new documentary evidence. This discovery reframes aspects of the diplomatic landscape surrounding Mary and the broader networks that linked England, France, and Catholic supporters across Europe, highlighting the complexity of early modern espionage and diplomacy. (Attribution: National Library of France; research team publication in Cryptology Journal).