This courtyard corresponds to the oldest and most important part of the palace, built for the Spanish Viceroys of Naples starting from 1600. Like in the grand palaces of the Renaissance, the square courtyard is divided into a two-level loggia designed by architect Domenico Fontana. Each side has five arches made in the local volcanic tuff or piperno. The frieze that divides the two levels is decorated with coats of arms and emblems of the House of Spain as well as those of the provinces of Castile and León, represented respectively by a castle and a lion. The symbol of the chivalric order of the Golden Fleece is carved above the arch leading onto the Staircase of Honour.
As part of the restoration work carried out following the fire that damaged part of the Royal Palace in 1837, the architect Gaetano Genovese eliminated the original windows on the piano nobile to create a series of larger windows. The elegant lanterns that illuminate the courtyard were added at the time of the Kingdom of Italy (after 1861).
Aligned with the main entrance is the Fountain of Fortune decorated with a statue commissioned by King Charles of Bourbon in 1742 and placed here in the mid-19th century.