Dom John IV (João; 19 March 1604 – 6 November 1656), also known by the Portuguese as John the Restorer (João, o Restaurador), was the King of Portugal from 1640 until his death in 1656. He restored the independence of Portugal from Habsburg Spanish rule by terminating the 60-year-old Iberian Union in which Portugal and Spain shared the same monarch, and by establishing the House of Braganza on the Portuguese throne.
Before becoming king, he was John II, the 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 was at its territorial zenith, spanning the globe.