John IV (Portuguese: João,; 19 March 1604 – 6 November 1656), nicknamed John the Restorer (João o Restaurador), was the King of Portugal whose reign, lasting from 1640 until his death, led to the Portuguese "restoration" of independence from Spanish rule. His accession established the house of Braganza on the Portuguese throne, and marked the end of the 60-year-old Iberian Union, by which Portugal and Spain shared the same monarch.
Before becoming king, he was John II, 8th Duke of Braganza. He was the grandson of Catherine, Duchess of Braganza, a claimant to the crown during the Portuguese succession crisis of 1580. On the eve of his death in 1656, the Portuguese Empire reached its territorial zenith, spanning the globe.