[3] As early as 1908, various pamphlets were being circulated by a former governess claiming that Cust fathered Diana Manners, and David Lindsay (a distant cousin of her mother) noted in his diary that the resemblance was said to be striking.

[citation needed] She became active in the Coterie, an influential group of young English aristocrats and intellectuals of the 1910s whose prominence and numbers were cut short by the First World War.

[5] The Coopers were friends with Edward VIII, and were guests of his on a 1936 yacht cruise of the Adriatic which famously caused his affair with Wallis Simpson to become publicly known for the first time.

[11] As Prime Minister Churchill's personal representative, Duff Cooper MP was unsuccessful in effecting a positive strategy, and he was recalled in January 1942, shortly before Singapore fell in February.

[12] In between accompanying her husband on his wartime appointments abroad, Lady Diana converted her three-acre property at Bognor Regis into a smallholding to provide her family with extra food in light of shortages and rationing.

[14] Between January and August 1944 the couple lived in Algiers, where Duff Cooper was appointed British Representative to the Free French Committee of National Liberation.

[15] Lady Diana focused her energies as a hostess on making an "Eden" of the couple's home for British civil servants stationed in Algiers, who were poorly housed in unheated and waterless lodgings and "had no retreats, amenities, sports or welcomes.

During this period, Lady Diana's popularity as a hostess remained undimmed, even after allegations that the embassy guest list included "pederasts and collaborators".

[18][19][20] The couple were known for maintaining an "open house" every evening where leading cultural figures and diplomats could come freely to socialize, while enjoying good food and plentiful liquor provided by the British government, both luxuries in Paris after years of wartime shortages.

The couple's decision to remain in France was controversial because it was contrary to diplomatic protocol; their continuing popularity as social figures and hosts in Paris effectively made their home a rival British Embassy.

[26] Lady Diana sharply reduced her activities in the late 1950s but produced three volumes of memoirs: The Rainbow Comes and Goes, The Light of Common Day, and Trumpets from the Steep.

Several writers used her as inspiration for their novels, including Evelyn Waugh, who fictionalised her as Mrs. Stitch in the Sword of Honour trilogy and elsewhere, and Nancy Mitford, who portrayed her as the narcissistic, self-dramatizing Lady Leone in Don't Tell Alfred.