He was the son of
Edward Tennant, who became
Lord Glenconner in 1911, and
Pamela Wyndham, a writer, and later wife of
Edward Grey, 1st Viscount Grey of Fallodon. His younger brothers were the eccentric
Stephen Tennant and
David Tennant, the founder of the
Gargoyle Club. Born at Stockton House,
Stockton, Wiltshire, which his father had just leased from Major-General A. G. Yeatman-Biggs, Tennant was educated at
Winchester College. At the age of seventeen he left school and joined the
Grenadier Guards in the early weeks of the
World War I. Tennant was known to friends and family as 'Bim', but the origin of this nickname is unknown. It has been suggested that he was engaged before his death to
Nancy Cunard, but a reliable source, Colin Tennant, 3rd Baron Glenconner, responded in a letter to a question on this point and stated that the suggestion was incorrect; Lois Gordon, Nancy Cunard's biographer, in her extensive research, never came across any hint of such an alliance either. ==Death and memorial==