John IV of Portugal

Born 19 March 1604, John was the 8th Duke of Braganza before he became king, grandson of a woman who had claimed the Portuguese throne during the succession crisis of 1580. In 1640 he terminated the 60-year Iberian Union — the period when Portugal and Spain shared a monarch under Habsburg rule — and restored Portuguese independence. That act established the House of Braganza as the new royal line. He ruled until his death on 6 November 1656, by which point the Portuguese Empire had reached its widest territorial spread across the world.