Classically crafted, with reconstruction in period costumes, and a former member of the Comédie-Française, Francis Perrin, in the leading role (and narrator), this documentary nonetheless reveals not-so-classic information on the absolute monarchy of Louis XIV. It allows you to revisit the Grand Siècle from behind the scenes.

“At the French court, spies are everywhere, distrust is required,” declares Antoine Rossignol (Francis Perrin) from the outset. This high-flying mathematician developed, two and a half centuries before the Enigma code of the Nazis deciphered by Alan Turing, the Great Cipher, a system making it possible to encode and decode all correspondence supposedly “sensitive” for the Crown.

“Under Louis XIV, everyone distrusted everyone,” underlines the historian of the Ancien Régime Jean-Christian Petitfils. Arrest of Fouquet, poison affair, morganatic marriage of the king with Madame de Maintenon… “The absolute monarchy is organized around secrecy. » Nicolas Robin, the actor who plays the sovereign, gives him the appearance of Machiavelli’s Prince.

“Interior Office”

Throughout his interminable reign (seventy-two years), Louis , according to his good will, to his relatives, to his subjects, to his rivals from other courts of Europe. To build his statue of Sun King as he wishes and anchor his status as absolute monarch. The sovereign provided the General Post Office with an “inside office”. A sort of dark cabinet responsible for sifting through suspicious missives, entrusted to Antoine Rossignol.

For the latter, it all began in 1628, under the reign of Louis XIII, at the seat of the bastide town of Réalmont (Tarn), held by Protestants. A young mathematician from Albi, keen on cryptology, is summoned to decipher a missive intercepted by the Catholic troops of the Prince of Condé, who will thus be able to capitulate the stronghold. Rossignol’s career is launched.

His dark cabinet allowed Jean-Baptiste Colbert to bring down his great rival, the superintendent of finance Nicolas Fouquet, in 1661. The mathematician then trained the king’s sister-in-law, Henriette of England, in encryption: she was sent to London in 1670 to his brother the sovereign Charles II, to convince him to renounce allying with the United Provinces (Netherlands) and Sweden.

Tool of absolute power

In 1672, the “office within” made it possible to thwart a new attempt at rebellion by the greats – an episode which had traumatized Louis XIV in his childhood, from 1648 to 1653. “A formidable test to verify the effectiveness of the secret services” , observes Rossignol-Perrin. The chief plotter, the Chevalier de Rohan, would be the last nobleman executed until the Revolution.

In 1715, upon the death of the Sun King, espionage became a true tool of absolute power, which his successor, Louis XV, used immoderately. The political police that will be deployed across Europe in the 19th and 20th centuries are already in the making.