A watercolour depicting guests about to dance a quadrille in the Waterloo Chamber; Queen Victoria partnered by the Emperor is on the left, opposite to the Empress Eugénie with Prince Albert. The Waterloo Chamber was built in the 1830s, though conceived over a decade previously by George IV and his artistic advisor at the time, and is the result of the roofing over of the Horn Court. It has changed remarkably little since, and has always housed the collection of portrait (known as the Waterloo Portraits) by Thomas Lawrence depicting the key players in the defeat of Napoleon. The composition of the group of portraits has changed over the years, particularly in the 1840s. Further embellishment of the upper walls and of the roof was undertaken by the decorating firm of J.G. and J.D. Crace in 1860. Originally the floor was covered by what seems to have been a removeable maroon carpet patterned with emblems of the civil and military honours of the Order of the Bath; in 1894 the Agra carpet which now covers the floor was installed.