Philip IV of Spain

Spain under Philip IV continued its involvement in the Thirty Years' War, fighting to maintain Habsburg hegemony in Europe. The war drained Spanish resources and led to military defeats, contributing to the decline of Spanish power.

Upon ascending the throne, Philip IV appointed the Count-Duke of Olivares as his chief minister. This decision placed the direction of Spanish policy in Olivares's hands for over two decades, shaping the kingdom's domestic and foreign affairs.

Philip IV appointed Diego Vel

Catalonia rebelled against Philip IV's rule, triggered by centralizing policies and the burden of war. The revolt lasted until 1652, weakening the Spanish monarchy and leading to a prolonged conflict that further strained the kingdom's finances.

Portugal declared independence from Spain, ending the Iberian Union that had existed since 1580. Philip IV's forces failed to suppress the rebellion, and the loss of Portugal marked a significant territorial and prestige blow to the Spanish Empire.

Spain under Philip IV signed the Peace of Westphalia, ending the Eighty Years' War with the Dutch Republic. Spain recognized Dutch independence, marking the end of Spanish dominance in Europe and the beginning of its decline as a great power.

Philip IV died, leaving a weakened Spanish Empire to his young son Charles II. His reign had seen the peak and decline of Spanish power, with economic troubles, military defeats, and territorial losses marking the end of the Spanish Golden Age.