Lady Elizabeth Foster is perhaps most famous as the mistress of the 5th Duke of Devonshire, living for many years in a 'ménage-à-trois' with him and his wife, Lady Georgiana Spencer (1757-1806).
Georgiana and Elizabeth were close friends, and Elizabeth accompanied her when she was exiled to Europe to give birth to her illegitimate daughter Eliza Courtney (1792-1859), following an affair with politician, Charles Grey (1764-1845).
However, three years after the Georgiana’s death, the couple married, and she cared for him at the end of his life.
Known affectionately as Bess, she was born in 1758 to Frederick Hervey, then Bishop of Derry and later 4th Earl of Bristol. Despite later succeeding to the Earldom and its estates, her father only attained this office in 1779, and so Bess was raised in what has been described as relative poverty, certainly compared to Georgiana and the Duke.
Her first husband was John Thomas Foster, and the two married in 1776. The marriage was not happy, with the couple separating around 1781. She was for many years prevented by her husband from seeing their two children, something that caused Bess great distress.
She would also have two illegitimate children with the 5th Duke, Caroline and Augustus, both of whom came to be raised at Devonshire House alongside the Duke’s legitimate children, including the 6th Duke of Devonshire.
The couple were only married for two years before the Duke’s death.
In her widowhood, Bess moved to London and then on to Rome, where she lived for the remainder of her life. She was a great patron of the arts in Rome, known particularly as an amateur archaeologist, funding excavations of the Forum.
She died in Rome on 30 March 1824, and was buried in the Cavendish Family Vault in Derby Cathedral.
