He was born at Barking, Essex on 21 August 1763,[2] the third son of Bamber Gascoyne (senior) and Mary Green and was educated at Felsted School.

In 1811, Gascoyne received a number of petitions from Liverpool resident John Bellingham, calling for him to take up his claim for compensation from the British government for a period of imprisonment he had suffered in Russia.

In May 1812, Bellingham entered the lobby of the House of Commons and shot Prime Minister Spencer Perceval dead.

When Gascoyne's motion was carried, the Government called the 1831 general election, in an attempt to gain a clear majority for reform.

[10] Gascoyne lost his seat on 4 May after the 1831 election, and died on 26 August 1841 at 71 South Audley Street, London, from an inflammation in his bowels.