Iberian Union

The Iberian Union was the dynastic union of Spain (Castile and Aragon) and Portugal, and of their respective colonial empires, that existed between 1580 and 1640 and brought the entire Iberian Peninsula, as well as Portuguese and Spanish overseas possessions, under the Spanish Habsburg monarchs Philip II, Philip III, and Philip IV. The union began after the Portuguese crisis of succession and the ensuing War of the Portuguese Succession, and lasted until the Portuguese Restoration War, during which the House of Braganza was established as Portugal's new ruling dynasty with the acclamation of John IV as the new King of Portugal. This was a personal union, so the Kingdoms of Portugal and Spain remained independent states, sharing only a single monarch.