Marie-Antoinette, born on 02 November 1755 in Vienna, Austria, who became the Queen of France and Navarre by marrying Louis XVI, entered one of the darkest chapters of the French Revolution when she died at the guillotine in Paris on 16 October 1793. Loathed by Republicans for representing the betrayal and greed of the elites, she still haunts modern France due to the wrongdoings of the Revolution and the Reign of Terror. Her rumoured relationship with the knight Axel de Fersen from 1774 until her death has never been confirmed and generations of historians have tried to decipher the letters between these two supposed lovers. There are even rumours that the heir to the throne, Dauphin Louis XVII (1785-1795) was their love child. De Fersen, who was stationed in Paris as the Swedish ambassador to France, corresponded with the Queen throughout the Revolutionary period, and on several occasions tried to help Europe’s monarchies to rescue the French royal family, to no avail. He fled France after Marie Antoinette’s execution. After his return to Sweden, his family and his descendants never publicly spoke of their forbidden relationship. To protect the state’s security, the correspondence was coded and cyphered using traditional methods of numbers and letters. But the most sensitive and controversial passages were crossed out in ink, making them illegible. These sections have still never been fully deciphered despite various analyses carried out over the past decade. But modern science, with its new testing techniques, has sparked hopes of revealing more secrets of this centuries-old love affair. The campaign, a collaboration led by the National Archives (where the original letters are housed), the Museum of Natural History (which provides the forensic analysis) and the Fondation de France (which finances the project) is based on a chemical analysis of vintage ink and sequencing of analysis by a high-definition scanner. The combination of techniques has allowed analysts to decrypt the never-before-seen passages in their original form which was made public last year.