On Vacation Guide Book Madrid | Page 29

M The first stone was laid in 1738 and the building was finally completed in 1751 , although sculptural decoration of the grounds and " external works " continued until 1759 , under the watchful eye of Sacchetti . Unfortunately , his work suffered from constant redrafting and was significantly altered by Francisco Sabatini , the architect of Charles III who was the first king to live in the Royal Palace , installing his court there in 1764 . Charles III , who already employed Corrado Giaquinto as his court painter when he arrived in Madrid in 1760 , invited two other painters who were very well - known in Italy – and therefore in Europe – to decorate his new home : the Venetian Giambattista Tiepolo and the Italian - trained German Antonio Rafael Mengs , his first official portrait painter . The frescoes painted by these two artists in the main rooms , and by their pupils in other parts of the palace , are one of the most impressive features of this royal residence , where Charles III and Charles IV would spend just eight weeks a year : in December , Easter week and part of July . Charles III ' s bedroom , which forms part of the private chambers of this illustrious monarch , still contains all the fixed furnishing designed by Sabatini for the entire main floor : solid mahogany doors   and window frames ; lavish Spanish marble archways , mantelpieces and friezes ; and stucco ceilings and frescoes . In the 18th century , the walls of the palace were lined with the best painting from the Royal Collection . The Throne Room and the Gasparini Room are the most representative of Charles III ' s personal tastes , showcasing a highly exuberant Italian interpretation of the Rococo decorative style . Charles IV added significant neoclassical elements and a range of French furnishings and Ferdinand VIII is to thank for the overwhelming collection of French bronze - and - glass chandeliers . The last decorative changes , transforming the Palace into its current historical state , occurred under the reign of Alfonso XII in 1879 . The chambers of Charles IV and María Luisa , which were used by all successive monarchs until 1931 , extend along the entire length of the eastern facade . These rooms are regularly used to hold royal audiences , since the Palace is still the official residence of the King of Spain . The Royal Armoury , hailed as the best European collection together with the Imperial Armoury of Vienna , which are both attributed to the Hapsburgs , was installed alongside the Alcazar by Phillip II and transferred to the current room in 1891 .