Crypt crackers have revealed the secrets of the lost letters of the beheaded Queen Mary Stuart

Secret encrypted letters written by Mary Queen of Scots while she was imprisoned in England by her cousin Queen Elizabeth I of England have been cracked by a multidisciplinary team of international codebreakers.

For centuries it was believed that the contents of the letters were lost. But computer scientist and cryptographer George Lasry, pianist Norbert Bierman and physicist Satoshi Tomokiye did not find them while searching for encrypted documents in the online archives of the National Library of France.

Scientists learned that Maria was the author of the papers only after they unraveled her complex encryption system. Their work translating 57 letters, published in the journal Cryptologia, reveals about 50 new ciphers previously unknown to historians.

“Queen Mary left an extensive collection of letters, kept in various archives. However, there was previously evidence that these archives were missing other letters from Mary Stuart, such as those referred to in other sources but which are nowhere to be found. The letters that we deciphered are most likely part of this lost secret correspondence,” suggest experts involved in deciphering the documents.

Mary’s correspondence, dating from 1578-1584, reveals fascinating details of her imprisonment. Most of them are addressed to the French Ambassador to England, Michel de Castelnau. He was a supporter of the Catholic Mary, who was under the tutelage of the Earl of Shrewsbury when she wrote them.

“When I deciphered the letters, I was very, very puzzled, and it seemed kind of surreal to me,” Lasry admitted. The cryptographer’s team is part of the interdisciplinary project DECRYPT, which involves several universities in Europe, with the aim of mapping, digitizing, deciphering transcriptions and deciphering historical ciphers.

“We’ve cracked the secret codes of kings and queens before and they’re very interesting, but with Mary Queen of Scots it was great because we deciphered so many unpublished letters and because she’s so famous. This is a truly exciting discovery,” said the specialist. He added that “together the letters constitute a vast body of new primary material on Mary Stuart – some 50,000 words in total – shedding new light on some of the years of her imprisonment in England.”

Let us remember that one of the most famous historical figures of the 16th century, Mary was first in line to inherit the English throne after her cousin Elizabeth. Catholics considered Mary the rightful ruler, and Elizabeth imprisoned her for 19 years because they saw her as a threat. After a life of imprisonment, Mary Stuart was executed at the age of 44 for her alleged participation in a plot to assassinate Elizabeth.

During her time in captivity, the Queen of Scots communicated with her companions and allies, making considerable efforts to recruit messengers and maintain secrecy. The existence of a confidential channel of communication between Mary and Ambassador de Castelnau is well known to historians and even to the English government of that time. But Lasry and his fellow codebreakers provide new evidence that this exchange had already existed before, in May 1578, and was active until at least mid-1584.

Using computerized and manual methods, the study’s authors transcribed the letters, which reveal the difficulties Maria faced in maintaining contact with the outside world, and how the letters were transmitted and by whom. Key topics mentioned in the correspondence include complaints about her poor health and conditions of captivity, as well as her negotiations with Queen Elizabeth I for her release, which she believed were conducted in bad faith. Also evident is her distrust of Elizabeth’s spymaster, Sir Francis Walsingham, as well as her hostility toward her cousin’s favorite, Robert Dudley. She also expresses her grief when her son James – the future King James I of England – was kidnapped in August 1582, and her thoughts that France had abandoned them.

The catalog of the National Library of France lists the letters as dating from the first half of the 16th century and relating to Italian affairs. However, the study’s authors say they “quickly realized that they were written in French and had no connection with Italy.” Their decipherment revealed verbs in the feminine form, several references to captivity and the name “Walsingham”, raising suspicions that they might be from the Queen of Scots. This fact was confirmed by comparing them with the text of the letters in the Walsingham papers in the British Library.

Commenting on the new article, Mary Stuart expert John Guy, who wrote a 2004 biography of the Queen of Scots, notes that this is the most significant discovery about the official monarch in a century.

“This discovery is a literary and historical sensation. Amazing! This is the most important new discovery about Mary in the last 100 years. I have always wondered whether the original letters with de Castelnau might one day turn up in the Bibliothèque Nationale de France, or perhaps elsewhere, unidentified due to encryption,” Guy said.

Now, according to experts, there is hope that this research will lead to future finds and details of events in the 16th century.

“In our article we present only the initial interpretation and summary of the letters. “More analysis by historians could lead to a better understanding of Mary’s years in captivity,” Lasry adds. “It would also potentially be great to work with period specialists to create an edited book of her letters, transcribed, annotated and translated.”