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.

[3] In 1911, Wallace joined the 2nd Regiment of Life Guards Reserve, gaining the rank of Captain, serving as adjutant from 1915 to 1918.

[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: 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).

[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.