300 Réis - Afonso VI Counterstamp 'Crowned 300' over '4 Reales - Felipe IV'

In 1663, Portugal was two years past its decisive victory at the Battle of Ameixial — still fighting to consolidate independence from Spain following the 1640 Restoration. Silver was scarce, and the crown had neither the mint capacity nor the bullion reserves to strike sufficient new coinage. The solution was pragmatic: Spanish colonial four-reales pieces, already circulating widely in Portugal, were counterstamped and revalued as Portuguese currency, effectively conscripting enemy silver into domestic service.

The host coins are Felipe IV issues, the monarch whose reign Portugal had formally rejected. Overstamping his coinage with a Portuguese royal cipher carried an implicit political charge that contemporaries would not have missed.