1 Real - Philip IV

The year 1656 places this cob squarely in the aftermath of one of the most consequential scandals in colonial minting history. Beginning in the early 1640s, assayers at Potosí — most notoriously Juan Ramón de Rozas — had been systematically debasing silver coinage, reducing fineness well below the mandated .917 standard and pocketing the difference. The fraud was uncovered around 1649, triggering mass executions and the recall of suspect coinage across the Spanish empire. By 1656, the mint was under tightened crown oversight, and coins of this date are generally accepted as struck to proper fineness.