Percy was educated at Eton College and St John's College, Cambridge, where he graduated Cambridge Master of Arts (MA Cantab) in 1805 and Doctor of Divinity (DD) in 1825; he was admitted DD ad eundem at Oxford University in 1834.

[1] Having taken holy orders, Percy married, on 19 May 1806, Mary, the eldest daughter of Charles Manners-Sutton, Archbishop of Canterbury, by whom in 1809 he was collated to the benefices of Bishopsbourne and Ivychurch, Kent.

He found Rose Castle, the episcopal residence, much dilapidated; he called in the architect Thomas Rickman, and the house was entirely remodelled.

The main cost was defrayed out of the episcopal revenues, but he spent his own money on the gardens, grounds, and outbuildings.

Among their children were: He married, secondly, in February 1840, Mary, the daughter of Vice-Admiral Sir William Hope Johnstone.