The Throne Room is the most spacious and dignified apartment of the Palace. Its original decor, executed from Rastrelli's design in 1753, was in the Baroque style, and included an abundance of gilded mouldings. A quarter of a century later, Velten redecorated the interior in the Classical style. Built on a rectangular plan, it is about twenty-four metres long and thirteen metres wide; its height is nearly equal to its width, and this adds to the general impression of loftiness and grandeur. The effect of spaciousness is enhanced by two tiers of arched windows with mirrors set between them, occupying almost the entire surface of the long walls. The light pours in from both sides. Views of the Upper and Lower Gardens open at right and left.
The inlaid floor, made from drawings of Bartolomeo Francesco Rastrelli, was retained by Velten. It is 342 sq. m in area, and is edged with a broad ornamental border. The dynamic and carefully balanced composition gives an added sweep to the vast interior.
Rastrelli's gilt carved decor was replaced by Velten with white Classical-style stucco mouldings. The mirror and picture frames are adorned with oak wreaths, bay-leaf garlands, palm fronds, and branches of oak and laurel. Acanthus scrolls linked by garlands form a broad ornamental band which runs along the coving. Trophies of arms tied with a tasselled baldric embellish the corner piers. The delicate pearl-grey tint of the walls sets off the white of the mouldings and gives a noble beauty to the colour scheme of the apartment.
The east wall, with the chair of state placed on a dais before it, is richly decorated. Its central portion is occupied by a large picture presenting Catherine II on Her Horse Brilliant, the work of Vigilius Erichsen. The picture has a moulded frame of oak garlands and is flanked by beautiful wreaths of oak leaves, roses, and laurels. Within the wreaths are medallions by Ivan Prokofyev, with allegories of Truth and Virtue (left) and Justice and Security (right). The rectangular reliefs over them show scenes from Russian history, one by Mikhail Kozlovsky, the other by Arkhip Ivanov.
Oil paintings form one of the most important elements in the decoration of the Throne Room. The west wall has four large canvases painted by Richard Paton (?) and showing episodes from the naval battle at Chesme. Four portraits by Buchholz are used as overdoors; twelve portraits in oval frames embellished with moulded flower garlands hang over the mirrors between the windows of the second tier.
The lighting fixtures fulfil an important decorative function: forty-nine gilt bronze sconces for four or six lights, distinguished by severe simplicity of design, and twelve chandeliers of crystal glass. The chandeliers, hung with sparkling smoke-coloured pendants shaped as oak leaves, faceted balls, and stars, further develop the effect of large space, and greatly add to the majestic beauty of the hall.
During World War II the paintings were evacuated; after the war they have occupied their usual places.
The Throne Room, restored in 1969, is a wonderful example of the synthesis of the arts in interior decorations.