It is thought that the first Roman settlement was built at this spot sometime after 123 BC. Later, when the city was under Moorish rule, an authentic citadel was built, and this served as a residence for the Vali (Moorish governor). It is from this period that the building has taken some of its current features. With the Catalan conquest, in 1229, the building was rebuilt and turned into a residence for the Mallorcan kings. With the disappearance of the Kingdom of Mallorca, the palace became a residence for viceroys and governors. Nowadays it is used as the official residence of the King and Queen of Spain, and it is also a museum and part of the building is occupied by the Military Headquarters.
The palace has a rectangular layout and is enclosed by walls which are flanked by square towers. Of these towers, the Torre de l´homenatge (Tower of Homage) stands out; this tower is also known as The Angel due to the 14th century copper sculpture of the Archangel Gabriel, who was the old patron saint of the city. Next to the street la Costa de la Seu there is the Torre dels Caps (Tower of the Heads), which is so called due to the fact that this is where the heads of executed prisoners were displayed. The current tower is a copy of Perpignan´s small castle. The façade looking out to sea has lost some of its defensive structure, with a series of arches and windows at different levels.
The main entrance is in front of La Seu, and it is from here that the Pati del Rei or Pati d´Honor (Courtyard of the King, or Courtyard of Honour) is accessed. This is where the Gothic-style Chapel of Santa Anna is located, the portal of which is reminiscent of Romanesque art, with mythical animals sculpted into the capitals, which support plain semi-circular archivolts and which are built from Pyrenean marble. Of the numerous rooms within the palace, the Sala del Tinell (also known as Sala del Tron) is of particular note; this was built in the 14th century and is identical to the same room in the Palace of the Mallorcan Kings in Perpignan. In the 16th century, when its roof collapsed, it was modified, with the addition of an intermediate floor supported by cross vaults. There is a second, smaller courtyard, called the Pati de la Reina (Queen´s Courtyard), which has a porched gallery and is where the Chapel of Sant Jaume is located. There are also some baths, very possibly from the Moorish period, which have been preserved.