Born in Brighton, Sussex, Capel was the son of Arthur Joseph Capel, a British shipping merchant, and his French-born wife, the former Berthe Andrée A. E. Lorin (1856–1902). He had three sisters: Marie Henriette Teresia Capel; Mary Josephine Lawrence Edith Capel; and Berthe Isabelle Susanna Flora Capel (married Sir Herman Alfred de Stern, Baron Michelham).
In the obituary of one of Capel's daughters, he was described as "an intellectual, politician, tycoon, polo-player and the dashing lover and sponsor of the fashion designer Coco Chanel". There are hints in biographies of Chanel about Capel's reputed (illegitimate) connections with the Capel Earls of Essex, but no connection has been established; his paternal family originated in Ireland. An alumnus of Beaumont College, he was already an apparently wealthy self-made man by 1909. Capel was killed in a car crash on Monday 22 December 1919, allegedly en route to a Christmas rendezvous with Chanel. He was buried with full military honours at Fréjus Cathedral on 24 December 1919.
Capel and Chanel
His affair with Chanel apparently began in 1909, when he became acquainted with the then 26-year-old mistress of his friend Étienne Balsan. Capel financed Chanel's first shops and his own clothing style, notably his blazers, inspired her creation of the Chanel look. The couple spent time together at fashionable resorts such as Deauville, but he was never faithful to Chanel.
Their relationship lasted nine years, and even after Capel married he continued his affair with Chanel until his death in late 1919. A roadside memorial was placed at the site of the accident, consisting of a cross bearing the inscription "A la mémoire du capitaine Arthur Capel, légion d'Honneur de l'armée britannique, mort accidentellement en cet endroit le 22 décembre 1919."
Marriage and children
In 1918, Capel married the Honourable Diana Wyndham, née Lister (born 7 May 1893—died 1983), a daughter of Lord Ribblesdale and widow of Captain Percy Lyulph Wyndham (killed in action, 1914), who was the half-brother of Hugh Grosvenor, 2nd Duke of Westminster. Diana's elder sister Laura was married to Lord Lovat, and another sister to Sir Mathew Wilson, 4th Baronet: after Capel's death, in 1923 Diana married Vere Fane, 14th Earl of Westmorland.
Capel had two daughters:
- Ann Diana France Ayesha Capel (28 April 1919 — 4 May 2008). Ann was married three times and had children with her first two husbands. In 1940 she married her first husband, George Ward (1907–1988), who in 1960 was raised to the peerage Viscount Ward of Witley. Ann and Ward divorced in 1951. She had two children with him: a son who died unmarried in his parents' lifetime at the age of 40, and a daughter. On 7 August 1951 she married Richard Thurstan Holland-Martin (born December 26, 1907 — died 24 January 1968), by whom she had two sons: Barnaby Robert (born 1952) and Giles Thurstan (born 1955 — died 4 May 2008); they divorced in 1966. Ann Capel's third and final husband was Peter Higgins.
- June Capel (born 1920 — died 26 September 2006), later Lady Hutchinson of Lullington. June was born after her father died, and he was apparently even unaware of her conception. Thus, he made no provisions for her in his will, and the will had to be contested to ensure that June got her fair share of her father's fortune (most of it subsequently stolen by a lawyer, according to Lady Hutchinson's obituary). In 1948 June Capel married Franz Osborn, by whom she had a son Christopher. Her second marriage took place in May 1966 to Jeremy Hutchinson, QC (born 28 March 1915). Hutchinson was the former husband of actress Peggy Ashcroft. and was created a life peer on 16 May 1978 with the title Baron Hutchinson of Lullington, of Lullington in the County of East Sussex.
Arthur Capel's living descendants today include the Honourable Mrs Patrick Tritton (daughter of his elder daughter Ann) and grandson Christopher Osborn, by his younger daughter June, Lady Hutchinson.
- French actor Olivier Sitruk played Capel in Coco Chanel (2008), a French-Italian-British television film, starring Shirley MacLaine as an elder Chanel.
- Alessandro Nivola played Capel in the film Coco avant Chanel (2009), starring Audrey Tautou as Chanel.
- Anatole Taubman played him in Coco Chanel & Igor Stravinsky (2009).
- Timothy Dalton played him in the film Chanel Solitaire (1981).
- Burke's Landed Gentry (18th and 19th editions) and The Complete Peerage give his correct forenames.
- Lady Hutchinson, obituary, Daily Telegraph, 4 October 2006. According to that obituary, Capel was a Roman Catholic and his wife had to convert to Catholicism to marry him, and her two daughters by him were raised as Catholics. 
- http://www.eclecticstyleblog.com/identified-the-bust-on-coco-chanels-mantelpiece/ Details of family background.
- The Times, 24 December 1919, p. 10: "Lord Rosslyn, telegraphing last night from St. Raphael, stated that Captain Arthur Capel, who was killed in an automobile crash on Monday, is being buried today at 2.30 p.m. at Frejus with full military honours".
- Cokayne, George Edward (1982). The Complete Peerage of England, Scotland, Ireland, Great Britain and the United Kingdom, Extant, Extinct or Dormant. X. Gloucester: A. Sutton. p. 773 note (c). ISBN 0-904387-82-8.
- "At this time in 1909, at the age of 26, she became friendly with an Englishman Arthur Capel, nicknamed “Boy”, who was one of Etienne [Balsan]’s friends...""Archived copy". Archived from the original on 2008-06-02. Retrieved 2014-04-10.
- ""That year was to prove a difficult one for Gabrielle as Arthur Capel decided that the time had come for him to marry into the English aristocracy. Arthur Capel was a very successful businessman and a keen polo player. Gabrielle hoped to settle down with him, but he was often away on business and was usually seen in the company of other women...."". Archived from the original on 2008-03-21. Retrieved 2014-04-10.
- "Even though he was married Capel still sought out Gabrielle when he was in Paris. But all this was to come to an abrupt end.... Capel was driving to Cannes for Christmas when he was involved in a fatal accident."
- The Times, Thursday, 13 May 1948; p. 7; issue# 51070
- The Times, Saturday, 1 June 1940; p. 9; issue#48631
- Genealogy of Robert Martin (1908—1897) Archived September 27, 2007, at the Wayback Machine. Thurstan Holland-Martin, fifth son of Robert Martin Holland, later Holland-Martin (R License, 14 August 1917), was the elder brother of Christopher Holland-Martin MP, and younger brother of Admiral Sir Deric Holland-Martin.
- At the time her youngest son's death was reported, she was described as the "late Mrs Peter Higgins".
- Lady Hutchinson, obituary, Daily Telegraph, 4 October 2006