His sudden death, apparently of a heart attack at the age of fifty-five, occurred in the presence of the physician and suspected serial killer John Bodkin Adams.

Edward was born at 37, Park Lane, Mayfair,[a][1] the son of Victor Cavendish and his wife, Lady Evelyn Petty-Fitzmaurice.

[4] Mobilised at the outbreak of the First World War, he was an aide-de-camp (ADC) on the Personal Staff[5] at the British Expeditionary Force's General Headquarters.

He was subsequently a minister in Winston Churchill's wartime government as a Parliamentary Under Secretary of State, for India and Burma (1940–1943) and for the Colonies (1943–1945).

On 26 November 1950, he suffered a heart attack and died at his home Compton Place, Eastbourne,[9] in the presence of his general practitioner, John Bodkin Adams, the suspected serial killer.

[12] No proper police investigation was ever conducted into the death, but the duke's son, Andrew, later said "it should perhaps be noted that this doctor was not appointed to look after the health of my two younger sisters, who were then in their teens";[10] Adams had a reputation for grooming older patients in order to extract bequests.

[10][13] The prosecutor was Attorney-General Sir Reginald Manningham-Buller, a distant cousin of the Duke (via their shared ancestor, George Cavendish).

[14] Home Office pathologist Francis Camps linked Adams to 163 suspicious deaths in total, which would make him a precursor to Harold Shipman.

The tax liability led to the transfer of Hardwick Hall to the National Trust, and the sale of many of the Devonshires' accumulated assets, including tens of thousands of acres of land, and many works of art and rare books.