The most notable of the many rooms are the state apartments. These were laid out from the 16th century onwards, and were enhanced in the style of those at Versailles during the 18th century. In the 19th century and again during the late 20th century, large-scale restoration of the state rooms consolidated the 18th-century style which prevails today. Designed as an enfilade and a ceremonial route to the throne room, the processional route begins with an external horseshoe-shaped staircase which leads from the court of honour to the open gallery known as the Gallery of Hercules. From here guests enter the Mirror Gallery, a long hall inspired by the Hall of Mirrors at Versailles.[2] This gallery leads to the first of the state rooms, the Officer's Room, where guests are greeted by court officials before an audience with the prince in the Throne Room. From the Officer's Hall the enfilade continues to the Blue Room. This large drawing room, decorated with blue brocade, is hung with Grimaldi family portraits and has chandeliers of Murano glass. The following room, the largest of the state apartments, is the Throne Room. Its ceiling and frescoes were executed by Orazio de Ferrari and depict the surrender of Alexander the Great. The throne, in the Empire style, is positioned on a dais, beneath a red silk canopy of estate surmounted by a gilt crown. The floors are of Carrara marble. All state ceremonies have been held in this room since the 16th century.[3]