The Buen Retiro, a royal retreat and pleasure palace, was built for Philip IV on the outskirts of Madrid in the 1630s. With its superb display of paintings by Velazquez and other contemporary artists, the palace became a showcase for the art and culture of Spain's Golden Age. A Palace for a King, first published to wide acclaim in 1980, provided a pioneering total history of the construction, decoration, and uses of a major royal palace, emphasizing...