Spanish-Portuguese Union

The Spanish-Portuguese Union occurred from 1580 to 1640 when the crowns of Spain and Portugal were united under a single monarch, King Philip II of Spain. This Personal Union meant that both countries shared the same king but maintained separate laws, cultures, and administrations. The union arose from a succession crisis in Portugal, as Philip claimed the throne. While it aimed to strengthen both nations against foreign threats, it led to resentment in Portugal, eventually resulting in their independence being restored in 1640 after a successful revolt.