settled at Twickenham at the end of his political career. Johnston had seen diplomatic service in Germany, first as King's envoy to Berlin and later working to secure the Hanoverian succession, and made frequent journeys to Hanover. It was said George I "often conversed with him very familiarly" and that Johnston was "a great favourite of Queen Caroline, who was much entertained with his humour and pleasantry". It was also said "he keeps out a very great rank, and frequently has Mr. Walpool and the greatest courtiers with him at his country house near London; and the King sometimes does him the honour to dine with him". The King is also recorded to have been a regular casual visitor to the house. He was one of the first to construct a home on the Thames in Twickenham during the 18th century. He procured a lease and commissioned architect John James to plan and erect a mansion – a project which spanned the following 35 years. The grounds were extensive, including the area now known as the Orleans House woodlands. Johnston created a fine garden which "included canals, an icehouse, a kitchen garden, a pleasure garden, a wilderness, a grotto and a fruit garden". A baroque octagonal room, designed by architect James Gibbs, was added in 1720 for entertaining George II's Queen Consort, Caroline, who regarded Johnston with great favour.
19th century
, Duc d'Orléans, while in exile, lived in Johnston's house at Twickenham between 1813 and 1815 and the house was later named after him.
20th century
Orleans House was demolished in 1926, and the area formerly occupied by the house used to quarrygravel throughout the 1930s. The outbuildings and octagon room were saved by the efforts of a local figure, the Hon. Nellie Levy, later the Hon. Mrs Ionides, who left it and her collection of 18th- and 19th-century pictures to the borough. It became a listed building in 1952 and was converted into an art gallery in 1972. In 1973, at the northern end of the former park were taken as the site of Orleans Park School.
21st century
The buildings and site were refurbished between 2005 and 2008 by architects Patel Taylor to incorporate an education centre and a cafe.
Orleans House Gallery
Orleans House Gallery, which opened in 1972, displays material from the London Borough of Richmond upon Thames' art collection. This includes a portrait of James Johnston by Thomas Gibson, paintings of Orleans House by Arthur Vickers and several other artists, and the Burton Collection, which includes artwork, personal effects and photographs of the explorer Richard Francis Burton. Orleans House Gallery is also the site of the London Borough of Richmond upon Thames' arts service and provides educational workshops for a wide variety of ages, using the converted stables and coach house as educational spaces. The gallery can also be hired as a wedding venue and for functions. The gallery reopened in March 2018 after a 17-month restoration project costing £3.7 million, which was partly funded by the Heritage Lottery Fund through a £1.8m grant. The Octagon Room has been restored, facilities improved and the upper floor extended to provide additional space. The painting of Queen Caroline has been relocated outside the Octagon Room.
Exhibitions
The gallery's previous exhibitions have included watercolours and sketches by Richard Dadd and, in 2003, the first major retrospective of Stephen Wiltshire's works. The gallery's exhibition Capability Now marked the 300th anniversary of the birth of Capability Brown.
