Gaspar de Crayer painted several portraits of Philip IV, probably commissioned by the Marqués de Leganés, who served as Philip’s emissary to the Spanish court in Brussels in 1627–28. Here the young king of Spain is presented in a magnificently decorated Flemish cavalry armor. He holds a commander’s baton in his right hand and wears an ornate rapier on his left hip. The composition follows a pattern in Spanish portraiture of depicting kings in fine armor, which was established decades earlier by Titian, for example in his portraits of Emperor Charles V and King Philip II. (http://www.metmuseum.org/art/collection/search/436049)