600 Réis - Afonso VI Countermark '600' over '8 Reales - Felipe IV, Spain'

In 1663, the Portuguese Crown faced a chronic silver shortage worsened by decades of the Restoration War against Spain. Rather than mint new coinage from scarce bullion, the solution was pragmatic: circulating Spanish eight-reales pieces — already abundant in Portugal through trade and military spending — were officially countermarked and revalued at 600 réis for domestic use. The host coins were struck under Felipe IV, the same Spanish king whose forces Portugal had been fighting since 1640.

The countermark program was authorized by Afonso VI's regency government. Spanish colonial macuquinas were the most common hosts, their irregular surfaces making clean application difficult.