NameHester Grenville 

Birth8 Nov 1720, Wotton Underwood, Bucks, England
Death3 Apr 1803, Burton Pynsent, Somerset, England
Misc. Notes
Information from Cynthia Glover (nee Coleman), whose great-great-grandfather was William Samuel Allen b.1843. (William's sister, Martha Allen, married Charles Oliver, youngest son of James and Ruth Oliver).
Wikipedia says, Hester Pitt, Countess of Chatham (8 November 1720 – 9 April 1803), 1st Baroness Chatham in her own right, “Hester Pitt, Countess of Chatham (8 November 1720 – 9 April 1803), 1st Baroness Chatham in her own right”.
Spouses
Birth15 Nov 1708, Golden Square, Westminster, England
Death11 May 1778, Hayes, Kent, England
OccupationPrime Minister of England