David Tennant was the son of Edward Tennant, who became Lord Glenconner in 1911, and the writer Pamela Wyndham, Lady Glenconner and later the wife of Edward Grey, 1st Viscount Grey of Fallodon.
He was the younger brother of the war poet Edward Wyndham Tennant and the socialite Stephen Tennant; Margot Asquith, author and second wife of the Prime Minister Herbert Henry Asquith, was his paternal aunt [REF].