[1] He was the elder son of Lieutenant-Colonel Derek Ernest Frederick Orby Gascoigne by his marriage in 1934 to Mary ("Midi")[3][4] Louisa Hermione O'Neill.

He carried out his National Service in the Grenadier Guards, including six months of duty at Buckingham Palace, before being posted to Germany.

[1] He was a nephew of Sir Julian Gascoigne, who was in charge of the Household Division during the coronation of Queen Elizabeth II, and of Terence O'Neill, Prime Minister of Northern Ireland (1963–1969).

[6] Gascoigne was the original presenter (from 1962) of the television quiz show University Challenge,[7] based on the US series College Bowl.

[6] In 1984 Gascoigne was parodied by Griff Rhys Jones in the alternative comedy series The Young Ones, in an episode entitled "Bambi".

[16] In 1998, Gascoigne presented a parody named Universe Challenge based on the sci-fi comedy series Red Dwarf.

[6] Gascoigne was the author of Murgatreud's Empire, a 1972 satirical novel concerning an entrepreneur who finds an island of pygmies, and trades them arms for treasure, recreating the development of European medieval weaponry and armour.

[18] This was originally written as a script, although the play was abandoned because of the impossibility of finding suitable performers for a cast of forty pygmies.

The same year he wrote a companion book, under the same title, with photography by his wife, Christina Gascoigne, published by Jonathan Cape.

[20] Gascoigne wrote Quest for the Golden Hare, a 1983 account of the internationally publicised treasure hunt associated with the publication in 1979 of Kit Williams' book Masquerade.

[6] On 8 August 1979, Gascoigne was witness to the burial by Williams of a unique jewelled, solid gold hare pendant in an earthenware jar "somewhere in Britain".

[23] In 1994 Gascoigne held the Sandars Readership in Bibliography and presented "From priceless perfection to cheap charm: stages in the development of colour printing."

[27][28] In August 2014, Gascoigne was one of 200 public figures who were signatories to a letter to The Guardian opposing Scottish independence in the run-up to September's referendum on that issue.

[33][34] An original pencil and chalk study for the painting Flaming June by Sir Frederic Leighton was found on the back of a bedroom door in the house.

[35] From 2018 until 2023, West Horsley Place was used as the filming location for the fictional Button House in the BBC TV comedy series Ghosts.