In the silence of an office in the Palace of Versailles, his hair bent over documents obscure to the layman, Antoine Rossignol worked to maintain the power of Louis XIV. If we are to believe this documentary entitled
Louis XIV and his spies
, the Sun King, who had to increase his vigilance as his power hardened, owes a lot to this mathematician.
The King's Dark Cabinet
His Majesty's best spy, discovered by the Prince of Condé during the Huguenot siege of Réalmont in 1628, had developed the most advanced coding system of the time. By substituting numbers sometimes for letters, sometimes for syllables. As well as proper nouns. It will also take the soldier and cryptologist Étienne Bazeries three years to fully decipher it, at the end of the 19th century.
No doubt it also took time for the authors to create this ambitious docu-fiction. Interviews with historians (Jean-Christophe Petitfils, Flavie Leroux...) alternate with honest scenes of reconstruction in wig and costume. Francis Perrin plays Rossignol – a curious career than that of the hero of
Mongeville
… And the Grand Siècle unfolds, from the arrest of the ambitious Fouquet to the conspiracy of Latréaumont, seen through the peephole of the king's dark cabinet.