King John IV of Portugal (b. Vila Viçosa, 1603; d. Lisbon, 1656)

Descended from King Manuel I and an illegitimate line from King John I, John became Duke of Braganza in 1630. Because of his royal heritage, even with its sordid elements, he had the strongest claim to the Portuguese throne after the revolution in 1640 cast off the rule of Philip IV of Spain. By unanimous decree of the people, he became John IV, king of independent Portugal. He served as king from 1640 until his death in 1656.

John was devoted to the arts, particularly music. He was a composer, and he also wrote a treatise on Palestrina and “a defense of modern music.” He collected one of the most valuable music libraries of the seventeenth century, which, unfortunately, was destroyed in the 1755 Lisbon earthquake.