The room occupies the site of the original Great and Withdrawing Chambers on the west side of the House. In contrast, the rooms on the east side were reserved for the King.
The Library was formed in about 1782, when the dividing wall between the two rooms was removed. The rebuilt chimneypiece incorporates a remarkable mosaic portrait of Robert Cecil which was made in Venice and presented as a gift to him in 1608.
Most of the chairs were made for the room in 1782 and have only recently been recovered in Nigerian goatskin to match the original crimson leather.
The windows overlook the West Garden and the Old Palace. The cast-iron rails of the balcony were supplied from Paris in 1875.