[3] Cornewall inherited the estates of his older brother, Frederick, on his death in 1783, and also those of a relative: Francis Walker of Ferney Hall.

[2][5] He was appointed master of Wigston's Hospital, Leicester, in 1790, dean of Canterbury in 1792, bishop of Bristol in 1797.

Cornewall married Anne Hamilton (d. 15 December 1795) on 19 June 1787, at Taplow, Buckinghamshire.

[2] The couple had three children:[5] Folliot Cornewall died at Hartlebury on 5 September 1831 aged 77, and was buried in the family vault at Diddlebury, Shropshire.

According to the Gentleman's Magazine, he "was possessed of fair scholarship, strong good sense, polished manners, and an amiable temper: and had passed a virtuous and exemplary life.