Sir Sacheverell Reresby Sitwell, 6th Baronet, (; 15 November 1897 – 1 October 1988) was an English writer, best known as an art critic, music critic (his books on Mozart, Liszt, and Domenico Scarlatti are still consulted), and writer on architecture, particularly the baroque. Dame Edith Sitwell and Sir Osbert Sitwell were his older siblings. Sitwell produced some 50 volumes of poetry and some 50 works on art, music, architecture, and travel. Life Sacheverell Sitwell was the youngest child of Sir George Sitwell, 4th Baronet, of Renishaw Hall. His mother was the former Lady Ida Emily Augusta Denison, a daughter of the 1st Earl of Londesborough and a granddaughter of Henry Somerset, 7th Duke of Beaufort. She claimed a descent through female lines from the Plantagenets. Born in Scarborough, North Yorkshire, he was brought up in Derbyshire and educated at Eton College and Balliol College, Oxford. In World War I he served from 1916 in the British Army, in the Grenadier Guards. After the war he went to Balliol College in Oxford but did not complete a degree, and was heavily involved in Osbert and Edith's projects. On 12 October 1925 he married a Canadian daughter of a wealthy banker, Georgia Doble (1905–1980). They had two sons – Sir Sacheverell Reresby Sitwell, 7th Baronet (1927–2009) and Francis Trajan Sacheverell Sitwell (1935–2004). He was also a member of White's and St James's clubs. Georgia Doble had difficulty adapting to married existence and missed the social life in London. Despite affairs on both sides, they remained deeply attached to each other until the end and never officially separated. The personal correspondence of Doble, preserved at the Harry Ransom Center at the University of Texas, include letters with David Stuart Horner and Frank Magro, Osbert Sitwell's partners, and friends like Lawrence Audrain, John Lehmann, Loelia Lindsay, René Massigli, Evelyn Waugh, and Mae West. Sitwell was an early member of the New Party, a group established in 1931 by Oswald Mosley and containing former members of the major British political parties. In his later life he withdrew from the publicity that attached to the Sitwells collectively, instead preferring to travel and concentrate on writing. He became the 6th baronet, inheriting the title when Osbert died in 1969. He was made a Companion of Honour in 1984. His main residence was Weston Hall, Northamptonshire, the family home and he served as High Sheriff of Northamptonshire