This work contains the inventory of the pictures in the Alcázar of Madrid on the death of Philip IV in 1666, including the identification and historical monitoring of these works in accordance with how they are reflected in the documents analysed. It therefore goes beyond a mere list of paintings; it recreates, room by room, the decoration that enlivened the Alcázar in the time of Philip IV. In addition to transcribing the 1666 inventory, it includes the transcription of those that supplement the view of the Alcázar, such as the will of Isabella of Borbón, which describes the Queen’s Oratory, or the inventory of 1686 which supplements the previous edition.