The site of the Royal Palace has been occupied since ancient times. It appears that there was a hill-fort on the site during Roman rule. The Arabs then built their Alcázar in the same place, which was later taken over by the monarchs of Castile. Peter I of Castile seems to have been responsible for transforming the Arab palace into a Christian one. During the reign of his successor, Henry II, there was a fire at the Alcázar. It was reconstructed during the reigns of Henry III and John II. In 1466 an earthquake in Madrid damaged the palace. Henry IV repaired the damage and by then the palace was a solid and impregnable construction. In 1537 Charles I commended new works to Covarrubias and Luis de Vega. They continued working on the project under [Philip II#PERSONAS#25] who ordered nearby land to be bought so as to construct stables and other rooms. He also built the Western Galley and had the Campo del Moro gardens laid out. The palace was extended to the point that it had five hundred rooms. It underwent transformations at the hands of its various inhabitants, who commissioned works to architects like Juan Bautista Toledo, Juan de Herrera, Juan Gómez de Mora, Alonso Carbonel and Juan Bautista Crescenti. However, once again the palace's fate was to be razed to the ground by flames. On the night of 24th December 1734 a terrible fire started, made worse by the strong winds blowing which made it very hard to bring under control. Philip V commissioned the architect Juan Bautista Sachetti to design the present-day palace. Building started in 1738 and the architects Baltasar Elgueta y Ventura Rodríguez were also involved. It could not be used until 1764, and Charles III was the first to live in it. The final retouches to the interior and ornamental decoration were completed in 1797.