David Euan Wallace, MC PC (20 April 1892 – 9 February 1941) was a British Conservative politician who was an ally of Neville Chamberlain and briefly served as Minister of Transport during World War II.

Wallace was born on 20 April 1892.^[1] He was the son of John Wallace, of Glassingall, Dunblane, Perthshire. His paternal grandparents were David Wallace, an ironmaster, and Janet (née Weir) Wallace. His aunt, Edith Wallace, was the wife of Maj. Robert Dunbar Sinclair-Wemyss.^[2]

He was educated at Harrow before attending the Royal Military College, Sandhurst.^[3]

In 1911, Wallace joined the 2nd Regiment of Life Guards Reserve, gaining the rank of Captain, serving as adjutant from 1915 to 1918.^[3] He was decorated with the award of the Military Cross (MC) after being wounded four times during the Great War.^[3]

After the War, he became assistant Military Attaché at the British Embassy in Washington, D.C. He acted as a special Commissioner for the North-East coast and acted as aide-de-camp to the Governor General of Canada in 1920.^[3]

Wallace was twice married and the father of five sons, four of whom died while serving in the military. On 26 November 1913 Wallace married Lady (Myra) Idina Sackville, daughter of The 8th Earl De La Warr and Lady Muriel Agnes Brassey.^[6] Lady Idina designed Kildonan House in Barrhill, South Ayrshire with the architect James Miller in homage to her childhood home, but they separated before it was completed.^[7] Before the marriage ended in divorce in 1919, they were the parents of two sons:

• David John Wallace MC (1914–1944),^[8] a Major in the King's Royal Rifle Corps who was killed in action during World War II while serving with the Special Operations Executive in Greece (during the Battle of Menina) and who married Joan Prudence Magor, a daughter of Richard Magor of Chelmsford, in 1939.^[9]
• Gerard Euan Wallace (1915–1943),^[10] a Wing Commander in the Royal Air Force Volunteer Reserve who was killed in a flying accident in Kenya in August 1943, aged 27^[11] and who married Mary Elizabeth Koch de Gooreynd, née Lawson, in November 1940.^[12]

On 10 May 1920, he was married to Barbara Lutyens (1898–1981), the daughter of architect Sir Edwin Lutyens and Lady Emily Bulwer-Lytton (a daughter of Edith Villiers and The 1st Earl of Lytton, the Viceroy of India and British Ambassador to France).^[13] Together, they were the parents of three sons:

• John Wallace (1922–1946),^[14] a Lieutenant in the Life Guards who died, unmarried, as a result of a general anaesthetic during a nose operation, while on active service.^[15]
• Edward Peter Wallace DFC (1923–1944),^[16] a Flight Lieutenant in the Royal Air Force Volunteer Reserve who was killed in action during World War II. He was unmarried.
• William Euan "Billy" Wallace (1927–1977), who was educated at Eton and University College, Oxford, and was a former escort of Princess Margaret, whom he had known since childhood.^[17] He married the Hon. Elizabeth Anne Hoyer Millar, daughter of The 1st Baron Inchyra and Anna de Marees van Swinderen (the daughter of Dutch diplomat René de Marees van Swinderen), in 1965.^[2] Princess Margaret, by then married to Antony Armstrong-Jones, attended the wedding.^[17][18]

He inherited a coal and iron fortune estimated at more than £2,000,000.^[3]

After undergoing a serious operation before Christmas 1940, Wallace died on 9 February 1941.^[3] His widow, who married Herbert Agar (the American journalist who was editor of the Louisville Courier-Journal) in 1945,^[19][20] lived another forty years before her death in 1981.^[21]