A moving and insightful treasure trove of her ‘lost letters’ has been discovered online, writes Gertrude Clark.

The “most important new find on Mary Stuart, Queen of Scots” as the historian John Guy described it, was revealed last month: the discovery of her so-called Lost Letters written in captivity in England to the French ambassador. The extra-ordinary thing is, the discovery wasn’t made by historians, but by code-breaking internet sleuths. You didn’t know that there are obsessives who trawl historical archives to find cipher-codes in old documents? Meet George Lasry, Norbert Biermann and Satoshi Tomokiyo. They discovered in the French Bibliotheque National online archive a trove of 57 letters written by Mary to Michel de Castelnau in code during 1578-84. For much of that time, the letters were safe; it was when Elizabeth I’s spymaster, Francis Walsingham, recruited an agent in the French embassy in 1583 that the correspondence was passed on to the authorit-ies. Fifty of the 57 letters are new to historians.