Gros blanc à la couronne - Jean II dit 'le Bon'

Jean II issued this coin while a prisoner of the English following his capture at Poitiers in September 1356 — one of the most catastrophic French defeats of the Hundred Years' War. The ransom negotiations that followed were staggering: three million gold écus eventually agreed upon for his release. Coinage reform and emergency emissions became a fiscal necessity as the French crown scrambled to stabilize a monetary system under extreme stress, with the billon content of circulating silver repeatedly adjusted to extract more revenue from a depleted treasury.

The .399 fine silver content reflects precisely that squeeze.