One Palace Green was originally built in 1868-1870 as a 17,000 sq ft mansion for George Howard, the 9th Earl of Carlisle (1843-1911), designed in Queen Anne revival style by renowned architect Philip Webb (photo), with interiors by William Morris of Morris, Marshall, Faulkner and company.

George Howard was an artist and MP whose guests at One Palace Green included William Gladstone, William Morris, Lewis Carroll and Alfred, Lord Tennyson. The famous green dining room designed by William Morris in the Victoria and Albert Museum is a precursor of one of the original interiors at One Palace Green.

Architect Philip Webb's other works include 19 Lincoln's Inn Fields.