Question: What is the date of death of William Dawnay, 6Th Viscount Downe's father?
Sentence (from "John Dawnay, 4th Viscount Downe"): John Dawnay, 4th Viscount Downe (9 April 1728 – 21 December 1780), was a British peer and Whig politician.
Relevant evidence: Yes