[4] Gascoyne became Lord Mayor in 1752, and was the first chief magistrate who occupied the present Mansion House, the building of which had been commenced in 1739 on the site of Stocks Market.

[6] Early in his mayoralty, 22 November 1752, Gascoyne was knighted on the occasion of presenting an address to the king; he was also a verderer of Epping Forest, in which office he was succeeded by his eldest son.

[7] He purchased large estates in Essex, including the buildings and grounds of an ancient hospital and chapel at Ilford, and the right of presentation to the living (see Impropriation).

Gascoyne died on 28 December 1761, and was buried on 4 January 1762 in Barking Church, in the north aisle of which is a large monument with an inscription, erected to his memory by his four children.

He married Margaret, daughter and co-heiress of Dr. John Bamber, a wealthy physician of Mincing Lane, who purchased large estates in Essex and built the mansion of Bifrons at Barking.

His daughter and heiress married the second Marquis of Salisbury, who took the name of Gascoyne before that of Cecil, and became possessed of the Bamber property, worth, it is said, £12000 a year (Munk's Roll).

A mezzotint portrait of Crisp Gascoyne by James McArdell, from a painting by William Keable, was published in the London Magazine for July 1753.