20 Réis - João Prince Regent

Portugal's copper coinage of this period was struck under João, who governed as Prince Regent after his mother Maria I was declared mentally incapacitated in 1792. The regency arrangement was constitutionally awkward — João held executive authority but could not formally reign, which explains the "Prince Regent" title on issues spanning nearly two decades before he finally became João VI following Maria's death in 1816.

Casa da Moeda de Lisboa had struggled with copper supply and production consistency throughout the late eighteenth century, and this denomination shows considerable variation in strike quality across surviving examples as a result.