Question: When did Francis Nathaniel Burton's father die?
Answer: 22 May 1787

Francis Conyngham, 2nd Baron Conyngham (born Francis Pierpoint Burton; 1725 – 22 May 1787) was an Irish peer and politician. Sir Francis Nathaniel Pierpoint Burton (26 December 1766 – 27 January 1832) was a British colonial administrator in Lower Canada and Irish politician. Burton was the younger of twin sons born to Francis Conyngham, 2nd Baron Conyngham (born Burton), and his wife Elizabeth, daughter of Nathaniel Clements