João IV (1604–1656), 8th Duke of Braganza, was acclaimed King of Portugal on 15 December 1640, following the restoration of Portuguese independence, becoming the first monarch of the Braganza dynasty. A descendant of João I, founder of the House of Avis, he was married to Luísa de Gusmão. His reign was marked by efforts to secure Portuguese independence and by the war against Spain.
Oil on canvas, dated 1640–1657, attributed to José de Avelar Rebelo. João IV is depicted half-length, in three-quarter view, wearing black attire with a white collar and cuffs and displaying the insignia of the Order of Christ. His left hand rests on the hilt of his sword. The Portuguese royal coat of arms appears in the upper right corner. The painting formerly belonged to the Royal College of Nobles in Lisbon.