Blanca - Enrique IV diamond, Seville

Enrique IV's monetary reforms were a political disaster almost immediately. His repeated debasements of Castilian billon coinage through the 1460s triggered the so-called "falsification crisis," in which counterfeit blancas flooded the market so thoroughly that merchants refused royal coin outright — a humiliation formalized when the nobility compelled him to accept the Sentencia de Medina del Campo in 1465. The Seville mint, one of the few with consistent output during this chaos, continued striking blancas under royal authorization even as his authority crumbled around him.

AB#834 corresponds to the later issues of his reign, struck after partial monetary reform attempts had already failed.